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Full text of "A half century in food and wine technology : oral history transcript, 1966"


University of California - Berkeley 



f 



University of California Bancroft Library/Berkeley 

Regional Oral History Office 



William V. Cruess 
A HALF CENTURY IN FOOD AND WINE TECHNOLOGY 

With an Introduction by 
Emil M. Mrak 



An Interview Conducted by 
Ruth Teiser 



Berkeley 
1967 



- 




Portrait of William V. Cruess 



Painted by Mrs. Marie Cruess 
Unveiled June, 1955 
Now in Cruess Hall, University 
of California at Davis 



All uses of this manuscript are covered by an agreement 
between the Regents of the University of California and 
William V. Cruess, dated 5 April 1967. The manuscript 
is thereby made available for research purposes. All 
literary rights in the manuscript, including the right 
to publish, are reserved to the Bancroft Library of the 
University of California at Berkeley. No part of the 
manuscript may be quoted for publication without the 
written permission of the Director of the Bancroft 
Library of the University of California at Berkeley. 



FOREWORD 

When the Regional Oral History Office asked Dr. Cruess if he 
would consent to giving an interview, he explained that as a result 
of having had two strokes, his memory and articulation were imperfect, 
but that he would try. This he did with determination and courage. 
In spite of difficulty at times in finding words to express his 
thoughts, he gave the interview in seven sessions, between October 19 
and December 15, 1966. They were held in his office in Hilgard Hall. 
The interviewer had been acquainted with Dr. Cruess and his work for 
some years. Dr. Cruess made careful preparations for each session, 
usually bringing notes. His discussions covered all major aspects of 
his work and his life, but it was determined in advance that material 
in his written memoir titled Biographical Data need not be duplicated. 

Editing of the transcript by the interviewer was confined mainly 
to deleting occasional repetitions and taking several sections out of 
the order of speaking to place them with related subject matter. Dr. 
Cruess himself then read it carefully, making some corrections and a 
few additions. 

Dr. Cruess has deposited in the Bancroft Library a copy of his 
autobiographical memoir, Biographical Data. It is the only copy known 
to exist at this time. He has also deposited a bibliography of his 



ii 



extensive writings, and he has presented to the University Archives 
copies of most of his papers. 



Ruth Teiser 
Interviewer 



15 November 1967 

Regional Oral History Office 

486 The Bancroft Library 

University of California at Berkeley 



INTRODUCTION 



by Emil M. Mrak, Chancellor 
University of California 
Davis, California 



iii 



Professor William V. Cruess unquestionably deserves to be called 
one of the fathers of modern food science and technology. During his 
early career as a chemist, he applied his talents primarily to the 
improvement of California wines. When passage of the eighteenth 
ammendment required him to turn his attention to other areas, Professor 
Cruess embarked upon a program of intensive research and development 
that has yielded enormous practical and theoretical results in the field 
of food preservation and distribution. 

Realizing that development of scientific methods to preserve and 
utilize food products was not keeping pace with advances in food pro 
duction with the result that increasingly large surpluses of many 
commodities were being produced in California Professor Cruess ini 
tiated the establishment of a Department of Fruit Products on the 
University s Berkeley campus. Originally a subdivision of the Depart 
ment of Viticulture, though it eventually attained full departmental 
status, in which there was several major accomplishments in the 
technology of food preservation. 

It was, for example, through the efforts of Professor Cruess and 
one of his talented co-workers, Arthur W. Christie, that sun-drying of 
fruits yielded in California, to mechanical dehydration. Naturally, 
industry came into the picture and developed dehydrators for sale, but 
Professors Cruess and Christie first set forth the basic principals and 
specifications that made such developments possible. 

Professor Cruess s work in developing new products to utilize 
surplus commodities also contributed greatly not only to the state s 
economy, but also to the consumer s delight. Three of his notable 
accomplishments in this area all now popular items on grocers 
shelves were fruit cocktail, fruit nectars, and bottled prune juice. 
Although others (including the present writer) participated in this 
work, it was Professor Cruess, with his enormous talent, energy, and 
desire to improve methods of utilizing food products, who almost single- 
handed, brought about the development of these products. 

If these were the sum of Professor Cruess s achievements, one 
would have ample reason to praise his service to both the food industry 
and mankind as a whole. But they are not. For when prohibition was 
repealed, Professor Cruess mobilized his staff and immediately set 
about helping the California wine industry reestablish itself on a 
sound basis. As one who was present at the time, I can assure this 
work was not at all easy. It required the rediscovery of efficient 
methods of growing and processing grapes and the reeducation of those 
who managed the industry. Among the problems that demanded solutions 
were those of what grapes to use and when to harvest them, what chemicals 
to add to the must, how to prevent bacterial spoilage, and what metals 
to use or avoid in processing the wine. Professor Cruess s labors in 
these areas were Herculean, and his achievements contributed greatly 
to the speedy development of one of the finest wine industries in this 
world. 



iv 



I should like to say a word also about the importance of 
Professor Cruess s contributions to the very foundations of modern 
food science and technology. When the Food Products Department was 
first established, the curriculum was essentially practical, lacking 
both breadth and a firm theoretical foundation. In strengthening the 
department, Professor Cruess built a staff of young men well-trained 
in the basic sciences, some of whom also had the practical outlook of 
the food plant operator. Under his guidance, the curriculum gradually 
acquired greater breadth and depth; with greater emphasis being 
placed on the basic disciplines chemistry, biochemistry, mathematics, 
engineering the groundwork was laid for what I terra today the full- 
spectrum program in food science and technology. In brief, Professor 
Cruess shares with Dean Prescott of MIT the honor of having placed 
the entire field of food technology, as we know it today, on a firm 
basis truly, a great achievement. 

Aside from his notable professional accomplishments, Professor 
Cruess was distinguished by a great dedication to his students. He was 
a demanding teacher who expected much of his students; but he in turn 
gave generously to them of his time and interest. He guided them, 
both professionally and personally, and in some cases even provided 
financial assistance to enable them to complete their studies. He and 
his charming wife often entertained his students in their home, inviting 
as many as fifty or one hundred for barbeques , even dances. And a few 
of his students were married in his home. The sincere mutual respect 
and affection between Professor Cruess and his students offers, perhaps, 
both a lesson and a hope to those who are now concerned about faculty- 
student relations in the high-speed, impersonal environment of the 
"multiversity." 

Because Professor Cruess s modesty has undoubtedly prevented his 
mentioning the many honors conferred on him in recognition of his 
achievements, it seems appropriate that I list a few of them. As I 
recall, one of the first he received was the Medal of the Legion of 
Honor, awarded by the French government for his research contributions. 
In this country, he was one of the first recipients of the Nicholas Appert 
Award of the Institute of Food Technologists. He was cited by the 
American Society of Enologists for his work with wines, and by the 
Olive Technical Conference for his tremendous contribution to the 
olive industry. The Forty-Niner Award, given annually at the con 
vention of the National Canners Association of America, was conferred 
on him for outstanding service to the canning industry. 

The University of California has not failed to recognize the 
achievements of one of its most renowned faculty members. Professor 
Cruess received an honorary Doctor of Law degree at the Davis campus , 
and the University s first substantial building, devoted entirely to 
food technology also at Davis was named in his honor. 



It is difficult to express adequately, in a few words, the 
extent of Professor Cruess s service to the University to the food 
industry, to those who have been privileged to know him personally, 
and to the larger community of mankind. His career has been marked 
by distinction in all its phases; and his modesty, selflessness, 
and dedication, as well as his professional brilliance, have won 
the highest esteem of his students, colleagues, and friends. He is, 
indeed, a great man. 



Emil M. Mrak 

Chancellor 

University of California 

Davis, California 95616 



CRUESS, William Vere (Ph.D.), Prof. Emeritus, Food Technology, 

313 Hilgard, Univ. of Calif., Berkeley, Calif. Home Add.: 951 

. Cragmont Ave., Berkeley, Calif. 

TECHNOLOGY, CHEMISTRY AND 

MICROBIOLOGY OF FRUIT AND 

VEGETABLE PRODUCTS, b. San 

Miguel, Calif., Aug. 8, 1886. s. 

William V. and Lucy (May) C. 

Edn.: B.S. Univ. of Calif., 1911; 

Ph.D., Stanford Univ., 1931. Hon. 

Deg.: LL.D., Univ. of Calif., I960. 

m. Marie Gleason, June 4, 1917. 

Exp.: Asst. in Zymology, Univ. of 
, Calif., 1911-14; Asst. Prof., ibid., 

1914-18; Assoc. Prof, of Fruit 
I Products, ibid., 1918-34; Prof., 
i Food Technology, ibid., 1934-55; 

Prof, of Food Technol., Emeritus, 
! 1955. Hon. Pos.: Past Chmn., 
Dept. of Food Technol., Univ. of 

Calif.,- Past Pres., Inst. of Food 
^i^ui.ji Technol. Mem.: Am. Chem. Soc.; 

Soc. Am. Bact.; Inst. of Food 

Technol.; Inst. Microbio!.; A.A.A.S.; Sigma Xi; Phi Lambda 
Upsilon; Alpha Zeta; Sigma Phi; Alpha Chi Sigma; Faculty Club. 
Author: Commercial Fruit and Vegetable Products, 1948, -1957; 
Principles and Practices of Wine Making, 1948, 1960; Lab. 
Manual of Fruit and Vegetable Products, 1923; Technol. of Wine 
Making, 1961. Contbr. to: Food Technol.; Food Rsch.; Industrial 
and Eng. Chem.; British Food Mfgs.; Food Engrng; Fruit Prod. 
Jour.; Canning Tr.; Canner-Packer. Awards: Chevalier du Merite 
Agricole, France; Officer du Merite Agricole; Am. Acad. of 
Microbiol.; Nicolas Appert Award of Inst. Food Technol.; 
Babcock-Hart Award, Inst. Food Technol.; Awards of Merit from 
Dried Fruit Assn. of Calif., Fig Growers Assn., Farm Bur. of 
Calif., Calif. Olive Assn., and Calif. Raisin Growers. Gen. Int.: 
Rsch. that has resulted in marked improvements in olive process 
ing, Frozen Foods, and Dehydration and Wine making. Areas 
of Rsch.: Processing and Preservation of Fruit and Vegetable 
Products, such as Canning, Freezing, Drying, Juicing, etc. 



Appeared in Leaders in American Science, 
Vol. V, p. 147, 1962-63 



CONTENTS 

FOREWORD i 

INTRODUCTION iii 

STUDENT YEARS 1 
(Interview 1, October 19, 1966) 

TEACHING AND RESEARCH IN THE WINE INDUSTRY 12 

(Interview 2, October 26, 1966) 15 

THE CALIFORNIA WINE INDUSTRY DURING PROHIBITION 22 

THE FIELD OF FOOD TECHNOLOGY BEGINS 28 

EXPERIMENTS ON FLOR SHERRY 31 
(Interview 3, November 2, 1966) 

OLIVE RESEARCHES 37 

PUBLICATIONS AND FOOD INDUSTRY ASSOCIATIONS 44 
(Interview 4, November 9, 1966) 

WORK WITH WINE FOLLOWING REPEAL 50 

FURTHER ON OLIVE RESEARCHES 57 

FROZEN FOODS 68 
(Interview 5, November 16, 1966) 

THE DEHYDRATION OF FRUITS AND NUTS 80 
(Interview 6, December 7, 1966) 

DEHYDRATION OF VEGETABLES 94 
(Interview 7, December 15, 1966) 

DR. MRAK, DR. JOSLYN.AND DAVIS 116 

PARTIAL INDEX 118 



STUDENT YEARS 

(Interview 1, October 19, 1966) 

Teiser: In your autobiographical memoir,* your discussion of your 
early farm years was so extensive that we will not have 
to retrace those steps. But I wondered if you were inter 
ested in food in a little bit of an abstract way as a 
child. Were you? 

Cruess: I don t think I was any more interested than the average 
person at that time. 

Teiser: I was interested in the diet you described. You mentioned 
that there was little fruit and there were few vegetables 
too. 

Cruess: We had mostly red beans and bacon or salt pork; we didn t 
have very much fruit at all. Our place was a dry farm, 
and our main diet was salt pork and beans, and homemade 
bread. And once in a while we had doves or quail. We 
had quite a large place with quite a number of quail and doves. 

Teiser: Were you a good student as a youngster? 

Cruess: Yes, I think I was a fairly good student. I had good grades. 



* W. V. Cruess, Biographical Data, 1964. A copy of this 
48-page typescript has been deposited by Dr. Cruess in The 
Bancroft Library. 



2 

Cruess: The teachers had the spelling bee complex at that time, so 
two or three times a month we would get together and spell 
each other down, and I could usually last until the last 
man or next to the last man. I could spell very well, but 
I was rather weak on mathematics. 

Teiser: You must have had to do some boning up in chemistry then. 

Cruess: Yes, I did. 

Teiser: Would anyone have been able to tell that you were headed 
for an academic career? 

Cruess: No, I don t know that they would. My father and Eddie 

O Neill [Professor Edmond O Neill], were students together 
when they were young, and O Neill kept in touch with him. 
He said I should take an academic curriculum instead of 
engineering. I had come with the idea of going into mechan 
ical engineering, but he persuaded me to join the College 
of Chemistry. 

Teiser: Who was Professor O Neill? 

Cruess: Professor O Neill was dean of the College of Chemistry. He 
and my dad went to school together until they were about 
ten years old; then he moved down south. I met Eddie, 
Professor O Neill, for the first time after I came to 
Berkeley, but my father gave me a letter to Professor 
O Neill telling him to please look out for us a little bit, 
which he did. At that time, the College of Chemistry had 



3 

Cruess: only six majors in chemistry, whereas now they have 
seventy-five or more. 

Teiser: How many people were on the staff then? 

Cruess: Oh, five or six, I guess. There was O Neill and Morgan and 
Biddle and Blasdale. I think there were about six or seven 
besides Professor O Neill. 

Teiser: Can you recall your first impression of the campus? 

Cruess: Yes. I had lived in Oakland for about six months before I 
came to Berkeley. About the only contact I had with the 
University was to go over and watch the football games. At 
that time we had five or six buildings that were used by 
the University, but I saw mostly the football and track and 
so forth and didn t give much attention to the academic 
side at that time. But the number of University buildings 
was fairly small, and practically all of the buildings that 
they had at that time have been replaced by newer buildings. 
And instead of having a couple of hundred students in the 
University --as you know now they don t have room to park 
for them all--we only had one or two cars on campus as that 
time, and automobiles were a curiosity. We got around with 
bicycles mostly, or on foot. Automobiles came later. 

Teiser: Did anyone ride horses on the campus? 

Cruess: Yes. The President of the University, Benjamin Ide Wheeler. 
Every morning he would ride to various points around the 



4 

Cruess: University and stop and talk to the students and others. 
Teiser: But students didn t have horses, did they? 
Cruess: No. Students had very much less money, and nearly all of 

them worked for part of their expenses. 
Teiser: I think it s fascinating that you actually lived in the 

Chemistry Department as a student. 
Cruess: In the junior and senior years, we lived in one of the old 

chemistry buildings. 

Teiser: Where was the building located? 
Cruess: It has disappeared now, but it was on the northeast side 

of the campus, very close to where the athletic field is 

now. The principal building there now is the Faculty Club. 
Teiser: You don t mention this in your autobiographical memoir, but 

you must have been a very good student at the University. 

Were you? 
Cruess: Yes. I was pretty good. I didn t get any honors, but I 

usually had A s or B s, and I never had any low grades. 
Teiser: Did learning come easily, or did you have to study much? 
Cruess: It came fairly easily, but I had to study quite a bit to 

retain it. I apparently didn t have any too good a memory, 

but I usually got by all right. 
Teiser: You started as an assistant before you graduated, did you 

not? 
Cruess: Yes. During the junior year, I had a job with the College 



5 

Cruess: of Chemistry setting up material for the lectures and 
handling the students papers and so forth. I didn t 
have anything to do with giving courses or correcting blue 
books or examination papers. It was mostly setting up for 
the lectures and taking the roll in a couple of courses. I 
was known as what they called a lecture assistant. My job 
was to assist the lecturers set up equipment for the lecture 
demonstrations, which they gave to us in person. 

Teiser: Were you paid for that? 

Cruess: Yes. Our pay at that time was not very high. It was 
twenty-five cents an hour. 

Teiser: You must have known how to live on very little. 

Cruess: Well, money in those days seemed to go further. A meal 

downtown, in the evening or at lunchtime, was only twenty- 
five or thirty cents, whereas now it s one-fifty or a couple 
of dollars. 

Teiser: Where did you eat downtown in those days? 

Cruess: In the College of Agriculture we had a room that had enough 
equipment for breakfast, so we made our own breakfasts, and 
at lunchtime I went to the club. I belonged to a University 
house club, La Junta Club. I didn t have enough money to 
actually live in the club, but I took one meal a day there. 
Most of my lunches were taken at the La Junta Club. And I 
went to the dances and other social events that the club 



6 

Cruess: had, but I spent the rest of my time at the College of 
Chemistry. 

Teiser: You didn t get your dinner at the club? 

Cruess: No. We ate our dinners downtown at a restaurant. At the 
beginning of each month we bought an eating card, I guess 
you might call it, and they punched a hole in that for the 
amount that we ate . 

Teiser: Were there some restaurants in Berkeley that catered just 
to students on that basis? 

Cruess: No. I think there were some down near the campus that 

catered to the University mostly, but most of the eating 
places were for the general public. 

Teiser: I remember when I was in college the inexpensive restaurants 
were usually Chinese restaurants. Was this one? 

Cruess: No, the one I went to was American, run by a white person. 
But we often took a trip to San Francisco to get a Chinese 
dinner. We could get almost twice as much Chinese food for 
the same amount of money. 

Teiser: Do you remember the name of the restaurant? 

Cruess: No. I know we went upstairs about two or three flights, 
and we were the only white people there. The man I ate 
with quite often when we went to San Francisco had a friend 
or two in Chinese restaurants. He knew them by their first 
name and so on, and we would chat with them when we had 



7 
Cruess: dinner. 

Teiser: Was Chinatown then still rebuilding after the earthquake? 
Cruess: It was rebuilding at that time, and a lot of it was under 

construction. 
Teiser: Back to the University you said that your first serious 

studies in what was to become your field were with 

Professor [Myer E.] Jaffa? 
Cruess: Yes, that s right. 
Teiser: What college was he in? 
Cruess: He was in the College of Agriculture. His subject was more 

or less nutrition and pure foods and so forth. He was head 

of the pure food and drug regulation of that Board of Health. 
Teiser: What was that position? Did it carry duties beyond the 

University? 
Cruess: Yes. He gave courses [at the University]. He also had an 

extension course where he went to various places. His work 

was mostly with the food value of various products and about 

digestion and so forth, as well as with food and drug 

regulation. 
Teiser: Did the state have pure foods regulations at that time, as 

it does now? 
Cruess: Yes. They were very much sketchier than they are now; they 

didn t have so many regulations. Much of Professor Jaffa s 

time was given to animal feed, such as the nutrition of milk 



8 

Cruess: cows. He gave his time more to farm animals than he did 
to human nutrition. 

Teiser: What was he like personally? 

Cruess: Well, let s see-- He was a man of medium height. Not 
much hair on his head. He wore a moustache. And was a 
good lecturer. 

Teiser: Was he a quiet sort of person? 

Cruess: He spoke quite easily and was a pleasant, good lecturer, very 
clear. He had a fine sense of humor. I think during my 
senior year I took care of his house for him, lived in his 
home while he and his children went to vacation in Yosemite, 
I remember, for a month. I watched the house. But luckily 
we were not molested. 

Teiser: Was he the first, or one of the first, to concentrate on 
nutrition studies? 

Cruess: Yes, I think he was. Agnes Fay Morgan, who retired a few 

years ago, was just starting in his department. He retired 
several years after I went to work for the University. 
Agnes Fay Morgan took over the work there and greatly 
expanded it, and made it a nutrition department. 

Teiser: You mention in your memoir Professor George Colby. He is 
still quite well remembered, is he not? 

Cruess: Yes, he is. 

Teiser: What sort of man was he? 



9 

Cruess: He was rather plump. He had quite a lot of weight. And he 
liked his wine and beer. One of his jobs was to look after 
the fermented products, the wine especially, and oh once 
in a while he would drink them. He was a chemist, and he 
didn t teach any courses, but he had two or three graduate 
students who worked under him. They didn t have any Ph.D. 
candidates, but they had quite a few Master s candidates. He 
was quite an offhand individual and enjoyed rather racy jokes 
and so forth. He was a good chemist, was a specialist mostly 
in the field of animal feeding. He was also a specialist in 
wine and wine chemistry and the making of wine, and worked 
quite often with Professor [Frederick T.] Bioletti, who was 
the head of the Department of Viticulture. 

Teiser: Professor Bioletti was very important in the development of 
wine studies, was he not? 

Cruess: Yes. He worked with Professor [Eugene W.] Hilgard, who was 
at that time head of the Department of Agriculture. Both 
he and Professor Bioletti were interested in wine making 
and wine chemistry. Bioletti was younger than Hilgard. 
Hilgard retired about 1910, I think, and Jaffa retired 
twenty or twenty- five years later. 

Teiser: What was Professor Bioletti like as a person? 

Cruess: He was a small man; he was a very short person, about five 
foot four or five. His parents were English. He had quite 



10 

Cruess: a bit of an English accent, and he wore a handlebar 

moustache which was neatly trimmed. He also had quite a 
lot of interest in foods, that is, the preservation of 
foods by canning and so forth. That s where I got my first 
interest in that subject, with him. But his primary interest 
was in wine making and viticulture. 

Teiser: At the time, then, there was more interest in the University 
in wine and food for human consumption? 

Cruess: Yes. There was a lot of interest in enology as it s called 
the technology and chemistry of wine making. 

Teiser: The study of zymology fed into the study of enology, did 
it not? 

Cruess: Yes. Professor Bioletti had all the courses in wine making, 
and zymology was one of them. The professor of zymology at 
that time was Professor Hans Holm. Professor Bioletti 
took over his course when Professor Holm took a leave of 
absence for a couple of years. Professor Bioletti had 
given the course for two or three weeks and then turned it 
over to me, because I had had the course in zymology and at 
that time I had just graduated from the University. He 
gave me the job of giving the lectures in the course in 
zymology. But we didn t have many students. I think we 
had three students at that time, and I talked until they 
got sleepy. It was my first teaching position. It was a 



11 

Cruess: course of lectures twice a week and a laboratory course 
also twice a week. So that was good experience. 

Teiser: Was that for one semester? 

Cruess: Yes. 

Teiser: Did all three of your students pass? 

Cruess: Yes, I think they did. 

Teiser: So that gave you a good beginning in your teaching career 
then? 

Cruess: Yes. 

Teiser: Had you intended before that to make teaching your pro 
fession? 

Cruess: I had gone to the University with the thought of graduating 
in mining engineering, but as it turned out I got this 
part time job with Professor Jaffa in which we set up the 
courses with laboratory experiments. 



12 



TEACHING AND RESEARCH IN THE WINE INDUSTRY 

Teiser: From that time on were you going to teach, or was there a 
possibility that you would work in the wine industry? 

Cruess: From the start with Professor Bioletti, it was about half 
and half. For example, I would try to give a lecture and 
laboratory course at the University except on Friday, 
Saturday, Sunday, and Monday. Then I would go back and 
lecture in the laboratory course for two afternoons. I 
would take the train to Martinez and under Professor 
Bioletti s guidance conducted experiments on wine making in 
a winery. At Martinez another graduate student, R. W. 
Bettoli, looked after the experiments in wine making at 
Martinez and came back and worked for three days a week in 
the laboratory at Berkeley. We conducted the wine making 
experiments for Professor Bioletti. And Professor Bioletti 
quite often came up and worked with us and watched what 
we were doing. 

Teiser: At what winery was this? 

Cruess: The first experiments were in the Colton Winery. That was 
in 1911. Professor Bioletti wanted us to carry on some 
experiments at the Colton Winery on fermentation on the 
use of pure yeast and sulphur dioxide. At that time, 



13 

Cruess: Professor Hilgard was in the last or the next to the last 
year of his academic career. The Colton Winery was owned 
by the former mayor of Martinez. And I think he was a 
good advocate of using wine. But also he was a very nice 
sort of fellow. 

Then, in 1912, we went to the Swett ranch. At 
that time I didn t have any courses during the fall semester, 
so I spent all my time at the Swett ranch during the 
fermentation season. John Swett had retired. He was the 
founder of education in California. Frank Swett, his son, 
and I carried out experiments on fermentation at the Swett 
Winery. 

Teiser: Was this the kind of experimentation that you would have 
done in the University? was it for research, or was it 
intended to make better wine for these wineries? 

Cruess: It was half and half. Mostly, the experiments that we 

conducted were applied to wine making. Not very highbrow 
or scientific. But they resulted in a printed publication 
about our work. We spent two summers at the Swett place, 
spending a couple of months each time. Then we went back. 
John Swett, of course, has long since passed away. 

Teiser: What sort of person was he? 

Cruess: He was a typical University scientist; he was quite a 
highbrow investigator. He was a very good teacher. 



14 
Cruess: He had a chin beard and was a little bit ferocious looking. 

He andlet s see, who was the man who did so much work on 

Yosemite? 

Teiser: John Muir? 
Cruess: John Muir and John Swett were pals more or less, and quite 

often I got in on their conversations and listened to their 

discussions of geology and so ongeological terms especially. 

They didn t agree on things, so the conversation would be 

quite spirited. 

Teiser: John Muir was not much of a highbrow, was he? 
Cruess: No, but he had done a great deal of reading. 
Teiser: So he was an equal arguer? 

Cruess: Yes. He and Mr. Swett did have some good arguments. 
Teiser: Was the Swett Winery a small commercial winery? 
Cruess: Yes, it was a commercial winery, not very large. But 

the Swett Winery had a very good reputation; it was well 

known for high quality. 
Teiser: Were they mainly table wines? 
Cruess: Yes, they were table wines entirely. There are two kinds 

of wines usually. The wines that are fortified with brandy 

were the sweet wines, port and sherry and so on. They 

didn t make that kind; they made dry wines. 
Teiser: Did they sell under their own label? 
Cruess: Yes. They sold them both ways. He made some wine for the 



15 

Cruess: larger companies to sell under their label, but most of 
the wine was labelled with the Swett company s label. 

Teiser: Did that winery disappear in the time of Prohibition? 

Cruess: Yes. It never was taken up again after that. John Swett 

had meanwhile died, and Frank Swett, the son, was interested 
in growing vines for the commercial planters. He was a 
nurseryman. He gave up the wine making business. When 
Prohibition came along, he abolished the winery. He had 
quite a large nursery near Stockton, and he was quite a 
prominent nurseryman. 

Teiser: Mainly grapevines? 

Cruess: Yes. Mostly grapevines and walnuts. He had quite a large 
orchard in which he grew walnuts and pears. Shortly after 
Prohibition, he became head of the Pear Growers Association. 

Teiser: That was a long period for men who were interested in wine 

making to survive. It was lucky that there were people like 
you whose memories of wine technology went back to pre- 
Prohibition days and could bring it up to the thirties. 
(Interview 2, October 26, 1966) 

Teiser: Could you tell us a little about the other wineries in 
which you worked as a young man? 

Cruess: I spent considerable time in the Dehay Winery. Mr. Dehay 
was the old barber of Cloverdale. When he retired, he did 
quite a little work on the growing of grapevines for wine 
making. His son was a graduate of the farm school at Davis, 



16 

Cruess: and he was a pretty good friend of mine. So one of the 
first things I did after taking the job with the College 
of Agriculture was to go to his place, the Dehay ranch in 
Cloverdale, and live there in the house with them for a 
couple of months. Young Dehay and I carried on various 
experiments on wine making. 

Teiser: Were they making table wines? 

Cruess: Yes, they were. 

Teiser: What was the nature of your experiments? 

Cruess: The experiments there at Cloverdale were on the control of 
fermentation. Ordinarily, various kinds of yeasts will 
grow, and some of them are good, and some of them may spoil 
the wine. We experimented on the control of fermentation, 
the comparison of various yeasts, and the use of sulphur 
dioxide to control fermentation. 

Near the Dehay place were two other small wineries, 
and I spent quite a lot of time in them. Actually they were 
fairly good sized wineries, but they would be called small 
now. That was in 1912 or 1913. One of them was the Smith 
winery; it was closed a long time ago. 

Teiser: Was the Dehay family an interesting one? 

Cruess: Yes. They were from France. Mr. Dehay came from the 

northern part of France. He made very good wine, and he had 
a kind of an interesting way of introducing the kids to the 



17 

Cruess: use of wine. Instead of giving them a full glass of wine, 
he gave them a glass mostly of water plus a small amount 
of wine. 

Teiser: Is that the traditional French way? 

Cruess: I think it must be. They start them off with a small 
amount of wine and gradually increase the strength. 

Teiser: Had he been a wine maker in France? 

Cruess: I don t know whether he was or not. He was primarily a 
barber, and wine was a side issue with him. 

Teiser: I wonder how much French tradition there was in wine making 
in those years in California. 

Cruess: It was talked about very much, but they had not taught 
wine making very much. In the University s College of 
Agriculture at Berkeley, Professor Bioletti had two courses-- 
a lecture course on wine making and a laboratory course that 
went along with the lecture course. But the class was 
quite small, usually one or two students at the most, 
because wines were cheap and because of the competition 
with France and Spain. There wasn t very much future for 
graduates of the University in wine making. For example, 
at that time twelve cents or thirteen cents a gallon was the 
going price, so they couldn t make enough to make it 
worthwhile. 

Teiser: What quality were the ordinary wines here then? 



18 
Cruess: The quality varied quite a bit. There was some high-class 

wine but much that was poor or not very good. 
Teiser: Could it be aged at that going price? Could they afford 

to hold it? 
Cruess: They tried to sell the wine quite young. They didn t age 

it very much in those days. 
Teiser: Did any of the wholesale distributors then ever age it 

themselves? 
Cruess: Yes. The big factor in the wine business was the California 

Wine Association--C. W. A. They had a large wine aging 

cellar near the bay, and they had several hundred thousand 

gallons of wine that they would age. The chief chemist 

and the man who knew the most about wine was Charlie Ash. 

He was very well versed in wine making. Their plant was near 

Richmond. 
Teiser: Where did a proficient wine chemist get his training in 

those days? 
Cruess: There were several graduates of enology colleges in France 

who had good training. So in a way it was the French science, 
Teiser: Did the California Wine Association at that time buy young 

wines? 
Cruess: Yes. They made wines on a large scale. The California 

Wine Association had several million gallons of wine each 

year. 



19 

Teiser: Did they have their own vineyards, or did they buy from 

independent growers? 
Cruess: Mostly independent growers. They were not so much in 

the grape growing business as in the wine making business. 
Teiser: Did they age the wines sufficiently to bring them to a 

higher quality? Was their quality considerably higher 

than the general level of the market? 
Cruess: The market price of wine was quite low at that time, so we 

couldn t afford to spend much money. But the California 

Wine Association made what is called a sound wine, a wine 

that kept well and didn t get sour, because they knew how 

to handle it. 
Teiser: Someone mentioned that in Europe even today you often get 

a ropy wine but that you never get a California wine that 

is ropy. 
Cruess: I ve only seen one or two samples of that kind of wine in 

California, and I think it is not very common in France. 
Teiser: Was it more common before Prohibition? Is it something 

that has been improved upon, or was it never common here? 
Cruess: It never was very common here. The principal wine 

spoilage organism was the Lactobacillus. The wines when 

they spoiled, they became lactic sour, but they found a 

good many years ago that this type of spoilage could be 

easily prevented by adding a small amount of sulphur 



20 

Cruess: dioxide in the process of wine making, and that is a very 
common practice now. 

Teiser: In Europe as well as here? 

Cruess: Yes. 

Teiser: Was that process first found here? 

Cruess: No. It developed first in France. 

Teiser: Where had Professor Bioletti gained his experience and 
knowledge of wine making? 

Cruess: His training came from France through Professor Hilgard and 
others. That is, Professor Bioletti graduated from the 
University of California. He came over to California from 
England quite young. He graduated from the University and 
got a job with Professor Hilgard on the chemistry and manu 
facture of wine, and he became quite well known as a 
specialist here. So the training that he got was from 
Professor Hilgard and from the French enologists. He learned 
a great deal with Professor Hilgard. I think soon after 
graduation from the University he took a job with Professor 
Hilgard. And Hilgard had studied in Germany and France and 
came to America quite young. So in a way Professor Bioletti 
was trained in the French methods by second hand so to speak. 
There were famous wine men, of course, in California 
who had training in France. One of them was . . .Pacottet. . . 
It s a peculiarity of this stroke business that what you used 



21 

Cruess: to know on the tip of your tongue escapes you. You are 
not able to remember it. 

Teiser: I wanted to ask you a little more about Bettoli. 

Cruess: Bettoli, who worked with me on the experiments at the Swett 
Winery and the Martinez winery [the Colton Winery] was a 
graduate classmate of mine. He graduated from Ag Chem 
[Agricultural Chemistry] at the same time I did, and he went 
to work for a winery which later became the Italian Swiss 
Colony. But he started out after graduation with a smaller 
winery in the Napa Valley. He became a very good wine 
maker; he had a good reputation. He died about twenty-five 
years ago. His name was R. W. Bettoli. 



22 



THE CALIFORNIA WINE INDUSTRY DURING PROHIBITION 

Teiser: What did he do during Prohibition? 

Cruess: For a few years, he and the Italian Swiss Colony attempted 
to make and sell concentrated grape juice for making wine 
in the home. Although it was successful from the scientific 
standpoint, the demand for grape juice for wine making was not 
very large. Bettoli died soon after Prohibition went into 
effect. He married and had a son, whom I used to see quite 
often but whom I haven t seen for the past twenty-five years 
or so. The son is a graduate of the University of California 
in mechanical engineering. 

The Italian Swiss Colony tried to make a concentrated 
grape juice known as "concentrate" that would keep, but demand 
was limited. It turned solid and was very difficult to get 
back into solution. If they did not concentrate to that 
point, the concentrate would be apt to get infected with 
yeast and spoil. It was quite a problem just to concentrate 
the juice to the optimum point. So making this concentrate 
for wine making for household use and for commercial use kept 
the Italian Swiss Colony going. They made enough to keep in 
business but not enough to make much money. That never 
became a very popular method of using the grapes. But it 



23 



Cruess: saved the vineyards; they kept in business and had 
the grapes when Prohibition was killed. 

Teiser: They continued growing and concentrate production 
throughout Prohibition, then? 

Cruess: Yes, they did. 

Teiser: Were there many wineries that were able to keep up 
any continuous operation like that? 

Cruess: Yes, there were quite a few. There was quite a 
big demand for grapes to make homemade wine and 
for concentrate of the grape juice for the same 
purpose. But the biggest demand was for the grapes. 
I think a person would get a license to make two 
hundred gallons without tax. He had to declare it 
and have the Prohibition department accept him to 
make sure that he wasn t a bootlegger. Of course 
many of them probably were. So the Italian Swiss 
Colony kept in business in that way. Other large 
producers were the California Wine Association of 
San Francisco, the Italian Vineyard Company, Guasti, 
California, and the Italian Swiss Colony of Asti, 
California. 

Teiser: Besides a little business, it must have taken a little 



24 

Teiser: faith and a fair amount of capital to continue. 

Cruess: Yes, it did. One of the main points of success I think was 
in having contact with the right people in government, that 
is, [to persuade them] not to clamp down too tightly on 
home wine making. 

Teiser: Were most of the home wine makers Italian? 

Cruess: Yes, they were. 

Teiser: Knowing Italian buyers must have been important. 

Cruess: Yes, that s right. Quite a large number of Italians went 
into the business. You had to get a man who was selling 
grapes, and he would make your two hundred gallons of wine 
for you at a reasonable price, and that was quite a flour 
ishing business. Italians were principally involved in it, 
because Americans wouldn t wait to age wine and so forth, 
and go to the trouble of crushing and pressing the grapes. 
They would get hold of hooch of some kind, most of it 
bootleg wine, bootleg whiskey, and alleged whiskey. The main 
trouble was taking precautions to see that the whiskey was 
not made with wood alcohol. A fair amount of wood alcohol was 
used. The food and drug people tried to prevent that, 
of course. There wasn t so very much of the wood alcohol 
used, because it is apt to kill or blind the user. It was 
not extremely common. But much of the liquor made at that 
time was very young, of course, and very powerful, and not 



25 
Cruess: very good. 

Teiser: Did some of the wineries make wine for church use? 

Cruess: Yes. A famous winery at Livermore made quite a lot of wine 

for the church. It was the Concannon winery, and it still 

is in business. 

Teiser: Aren t most sacramental wines sweet and fortified? 
Cruess: It depends. There is more sweet wine than table wine, but 

there are both. There is one man who is very famous for 

his sacramental wines. I knew him very well, and he died 

just about two years ago. His sons were graduates of Notre 

Dame. He was American. He fought in the Spanish American 

War, and his name was Joseph Concannon. 
Teiser: Were the large wineries able to make the two hundred gallon 

quotas for people, or did that have to be individual 

enterprise? 
Cruess: They d usually sell the concentrate or the grape syrup, 

which they would deliver to you in the barrel. The man who 

made the wine was near the man he was making it for. 
Teiser: Was there an attempt to market more table grapes? 
Cruess: They were mostly wine grapes, not suitable for the table. 

The Italians wanted a red wine usually, and the red wine 

grapes are not suitable for table use. 
Teiser: Are they suitable for raisins? 
Cruess: They are not very suitable for raisins. One of our 



26 

Cruess: experiments after Prohibition was to study the concentration 
of grape juice to be used supposedly in making grape juice. 
The real purpose for all of this was to make wine. A large 
amount of wine was spoiled from inexperience because often 
it was made by someone who had not made wine before. 

Teiser: Was Cresta Blanca an old winery? 

Cruess: That was started by a graduate of the University, way back. 
His brother was a famous wine specialist, enologist, a 
graduate of the University. There were two brothers, Charles 
and Clarence Wetmore; both were graduates of the University. 
Three of these [Livertnore Valley] wineries were quite famous 
at that time and sold quite a few grapes and grape juice 
for wine making. 

Teiser: Did Cresta Blanca operate that way through Prohibition? 

Cruess: Yes. They made pasteurized grape juice. 

Teiser: Is that just for table grape juice use? 

Cruess: Yes. Most of their grapes were sold fresh in twenty-five 
pound and fifty pound boxes for making homemade wine. 

Teiser: Did you make wine at home during Prohibition? 

Cr.uess: No, I didn t. I made only small amounts for experimenting. 

However, I was well supplied by a friend who made two hundred 
gallons for family use. 

Teiser: Was the Wente Brothers winery started before Prohibition too? 

Cruess: Yes. 



27 

Teiser: Did it survive in a similar fashion? 

Cruess: Yes. They went through the Prohibition period selling 

fresh grapes principally. Soon after Prohibition went into 
effect, there was a very lively demand for fresh grapes for 
making wine. Wente shipped quite a few that went into 
wine making. 

Teiser: Then you must have had to shift your career when Prohibition 
came along. 



28 



THE FIELD OF FOOD TECHNOLOGY BEGINS 

Cruess: Yes. 

As Prohibition was coming on, I went into other 
work. I started a course in the preservation of fruits for 
making various nonfermented products. I studied also the 
production of canned fruit. That s how the food technology 
work was started. 

Teiser: That perhaps was the one good result of Prohibition. 

Cruess: Yes. So far as we re concerned. Out of that has come the 
large building at Davis for the study of unfermented food 
products fruit and vegetable products like preservation 
by freezing and canning. 

Teiser: Were there at that time other food technology courses given 
in the United States? 

Cruess: Well, there was some work at the University of Oregon. That 
is, at the College of Agriculture in Corvallis. When Pro 
hibition went into effect, they built up their research on 
various products like loganberry juice canning and so forth. 
Their work and ours were more or less simultaneous. One 
professor of horticulture worked on experiments with logan 
berry juice. He and I started at about the same time. His 
name was Professor C. I. Lewis and was succeeded by Professor 



29 

Cruess: E. H. Wiegand. 

Teiser: Were your teaching efforts and your research efforts 
similar at that time? Both in the same field? 

Cruess: Yes. The first work that I did at the University was mostly 
in wine making. After Prohibition it was entirely on un- 
fermented products. 

Teiser: What were some of those researches? 

Cruess: I think the earliest work was on unfermented grape juice. 
I worked more with the liquid products. 

Teiser: Did you do some work in that period on dehydration? 

Cruess: Yes, we did. One thing that happened there were people who 
bore the expense for the investigation of various uses of 
fruit or grapes unfermented products. And shortly after 
Prohibition, the University was given funds for research on the 
dehydration of fruit at Davis and carry on experiments there 
on the making and utilization of dried wine grapes. That is 
why the study of dehydration and sun-drying of grapes got 
started. That is how we started on the concentration of 
juices and dehydration and the making of other products from 
wine grapes. So for two or three years we spent most of our 
time at Davis during the grape season. I remember I had a 
course in co-operation with Professor Christie. A. W. 
Christie and I oscillated between Berkeley and Davis. I 
would spend two or three days down here on research on the 



30 

Cruess: production of grape concentrate and dried grapes. Then 
I would go back, and Christie would carry on for two or 
three days. Professor A. W. Christie later went with the 
Walnut Association for a number of years. In fact he 
worked for them long enough to reach retirement. He did 
more than any other man on the drying of walnuts. Com 
pletely revolutionized the method of drying. 

Teiser: In those years, how long did it take you to get back and 
forth between Berkeley and Davis? 

Cruess: We went by train. I think it was a little over an hour. 

Teiser: How did you get from the station to the campus at Davis? 

Cruess: We d usually walk out. Or if somebody were going through 
with a car, we would get a ride. Sometimes it was not a 
car but a horse and buggy. In those days the use of autos 
was more or less just beginning. 

Teiser: I suppose no faculty member was wealthy enough to own one. 

Cruess: Oh, by 1918 to 1920 quite a few of the faculty owned auto 
mobiles . 



31 



EXPERIMENTS ON FLOR SHERRY 
(Interview 3, November 2, 1966) 



Cruess: We might discuss the experiments on flor sherry. 

Teiser: Did the flor sherry experiments come out of some visits you 
made to Spain? 

Cruess: They were started before I made the trip to Spain. To tell 
the truth we meant to visit Spain at that time, but the war 
was still going on. The Civil War was still operating when 
we made our last visits, so we didn t get to observe the 
Spanish method of making sherry in actual visits. But we 
got the information from several of the Spanish investigators 
who came to Paris. There was one man in France who did want 
to work by the Spanish method; another was in South Africa. 
So the flor yeast, the yeast that is necessary for developing 
the Spanish type of sherry, we had not perfected the method 
of growing under California conditions. There are flor 
yeasts naturally occurring on Spanish vines, but in California, 
until twenty or twenty- five years ago, there was no flor sherry 
present except some that may have been brought in. In other 
words, the Spanish type flor sherry yeast did not occur in 
California. It did occur in South Africa and Spain, of 
course. So the major problem with flor sherry was to get it 



32 

Cruess: to grow under California conditions and to develop the 
flavor that we desired. 

Teiser: What was the method that California sherry makers had been 
using then? 

Cruess: There was no attempt at that time to make a flor sherry that 
was the Spanish type sherry. We merely fortified, that is, 
we added alcohol sufficient to keep the product. They made 
a sweet wine without growing the flor yeast, so the flavor 
of the American sherry was more or less neutral. It didn t 
have the flavor of Spanish sherry. 

Teiser: Was there any other place in the world where they made sherry 
without flor, or was this an American development? 

Cruess: Without the flor they made a type of fortified sherry in 
France, and in California we just fortified it. 

Teiser: Was flor desirable because it gave the sherry a better 
flavor? 

Cruess: Yes, I think that s the reason for it. It s quite a 

complicated process to develop the flavor. It takes at least 
two years . But in Spain the flor sherry may be in the oper 
ation of being made over a period of twenty-five years. Each 
flor sherry is made up of one to maybe fifty different wines. 
A wine that is to be made into flor sherry may be kept for 
ten to twenty years or longer. So they put in one gallon of 
new wine, and blend it in with fifty gallons of partially 



33 

Cruess: aged wine and flor yeast, and age it under flor. In the 
process they get one hundred gallons of flor wine. 

Teiser: So it is always being added to? 

Cruess: Yes, it is always being added to but not in large amounts. 
The sherry is made in one hundred fifty gallon barrels, 
and each solera may have fifty or more barrels. 

Teiser: It s a complicated system, isn t it? 

Cruess: Yes. 

Teiser: Is this what they call the solera system? 

Cruess: A solera may contain a thousand or more barrels. 

Teiser: There is a good explanation of the process in the bulletin 
that you wrote on the flor sherry process, Bulletin 710, 
dated 1948.* Had you by then developed a whole system that 
had been put into use here? 

Cruess: Yes. There were fifteen different wineries that were using 

this process experimentally, more or less under our direction. 
Some of them continued for quite a while to make flor-type 
sherry, and some just used the process for two or three years 
to find out how it worked. And they discontinued the 
experiments after a short time. Some of them were wineries 



*See Cruess, W. V., Investigations of the Flor Sherry Process, 
Bulletin 710, October, 1948, College of Agriculture, 
University of California, Berkeley; 40 pp. 



34 

Cruess: that made only unfortified wines, whereas all sherry has to 
be either fortified by adding brandy or it has to develop 
naturally by the flor process. It s all under the government 
supervision; it has to be done just so. The wines that we 
made experimentally were held for just one or two years to 
see how they worked. 

Teiser: Some of the wineries continued making them though? 

Cruess: Yes. Almaden has a flor sherry, also the [Louis M.] Martini 
wine company. We had one at Italian Swiss [Colony]. The 
enology laboratory at Davis developed a shorter process in 
the course of their research. By the shorter process, they 
could make wine similar to the Spanish flor wine, but it is 
not as flavorful. Apparently the flor process has to be 
employed to get the maximum flavor. The shorter California 
process, two years or so, gives the wine somewhat of a 
flor character, but not equal. Whenever you shorten the process 
greatly, as you do with the short bulk method of making sherry, 
you have less flavor. 

Teiser: It is a bulk method? 

Cruess: Yes. Instead of using the small barrels, fifty to sixty 

gallons, we can make sherry in bulk, in a tank of two thousand 
to ten thousand gallons. Although you can produce the film 
in this process, the flavor is not equal to the Spanish flor 
process. 



35 

Teiser: Do they get a film over the top of the whole tank? 

Cruess: Yes. Cresta Blanca was one of the places where they were 
using the bulk process for Spanish flor. The bulk process 
didn t use film , and the flor flavor did not develop fully. 

Teiser: This is basically a problem of economics, isn t it? 

Cruess: Yes. I think that only Louis Martini and Almaden are 

using the flor process now commercially. They are using the 
old flor process. In Almaden they have a large number of 
barrels under the flor process. In fact they have old, 
used barrels that some of the others had been using experi 
mentally. That is, some of the large companies could sell 
ordinary sherry at a profit, but when they tried to make the 
Spanish flor type of sherry, it was too costly, and they 
couldn t be bothered. 

Teiser: How long did it take you to work out the system in your 
experimentation? 

Cruess: All we did was adapt the Spanish process to California 

conditions. We didn t develop anything very new. A new 
method of making Spanish type sherry was developed by the 
Department of Viticulture and Enology at Davis. The way in 
which it was done was to pump air through the tank of wine, 
and keep it closed, and the oxygen, instead of being taken 
by a film and then from the film to the wine--the wine was 
aged with air under pressure. Instead of getting the oxygen 



36 



Cruess: from the film growing on the surface, it was obtained by 

aging the wine in a closed system. It was a bulk process, 
and it gave the wine more or less a Spanish type flor 
[flavor] within thirty days instead of taking three years 
or longer. But although it gave somewhat of a flor wine 
taste, it was not perfect. It was good enough to be used 
in big wineries. 

Teiser: Is Cresta Blanca using the bulk flor process now? 

Cruess: Yes, I believe they are. 

Teiser: I remember that the California Wine Association was making 
some, very small quantities, and was blending it with their 
other sherries. Is that correct? 

Cruess: Yes. It had some flor sherry. 

Teiser: I think you re being very modest. I want to put on the 
record that the credit for bringing the flor process to 
California is yours. Is that a correct statement? 

Cruess: Yes. I think that is correct, although it was coming at the 
time, and it would have come without me. Our work hastened 
it, however. * 



* See also p. 54. 



37 



OLIVE RESEARCHES 

Teiser: There have been a number of instances in which you have 
studied European processes for food technology and 
preservation too and adapted them to California uses, have 
you not? 

Cruess: Yes, I think we have. 

Teiser: I mean you personally. Didn t you bring a good deal of 
information to our olive industry by drawing on European 
technology? 

Cruess: I did a lot of work on the Spanish process of making Spanish 
type pickled olives--green olives. We did quite a lot of 
work on making green olives, shortened the process, and got 
it under control. But it s so much less expensive to grow 
olives in Spain and to make pickled olives from such fruit 
that California cannot grow and make that type of pickled 
olives on a large scale and make it pay. So for the Spanish- 
type green olives we use the small fruit and fruit that is not 
quite good enough to be pickled for canning. It s largely a 
matter of size. Lindsay Ripe Olive Company is the largest 
maker of Spanish-type green olives [in California], although 
one of the companies south of Lindsay, Early California Foods, 
is using the process. The Click Olive Company and the Smith 



38 

Cruess: Olive Company are using the process quite successfully. 

Teiser: Does this give them a use for their undersized olives 
that they didn t have before? 

Cruess: Yes. It gives an outlet for the smaller olives that are not 
quite large enough for canning. 

Teiser: So that much of the process has survived? 

Cruess: Yes, it has. Lindsay, Click, Smith, and Early California 
Foods all use the process. 

Teiser: You have done a great deal of work with the olive industry 
early to late, have you not? 

Cruess: Yes. I first became interested back in 1914 or 1915 and have 
been working on it ever since. So my two main lines of 
investigation and experimentation are olives and wine, 
although a large amount of my time had been given to other 
things, like the canning of fruits and dehydration. 

Teiser: What other lines of investigation did you carry on with 
olives? 

Cruess: One thing that happened to the olives was botulinus. Many 
years ago, the industry was almost wiped out, because in 
three different occasions the olives spoiled, and the people 
who used them didn t realize that the spoiling might develop 
a poison. 

Teiser: That must have been hard to live down. 

Cruess: Yes. So for a while the ripe olive industry was at a 



39 

Cruess: standstill practically. 

Teiser: Botulinus affected only black olives? 

Cruess: Yes. It is caused by the growth of an organism that can t 
grow if there is very much acid, so anything that is sour 
never develops botulinus. And the California ripe olives, 
of course, had been treated with lye during the pickling 
process, and that destroyed any acid. So there was no acid 
to hold the organism in check. They used the temperature of 
boiling water for sterilizing canned olives, and it takes a 
very much higher temperature of 240 F. , which was necessary 
to sterilize ripe olives. Some softening occurs, and very 
important changes in flavor. Olives that are pickled by the 
California process and heated to a high enough temperature 
to prevent the growth of botulinus change in flavor and 
soften. So we had to modify the process so that the olives 
that were canned would be free of surplus lye action and could 
be sterilized without softening too much or changing in flavor. 
Our part in the process was merely to modify the canning 
process so that the olives would not change too much in flavor 
under the higher temperature used . 

Teiser: You published a bulletin on that, did you not? 

Cruess: Yes.* 



* Bacterial decomposition of olives during pickling. With 
E.H. Guthier. Berkeley: University of California, 1923. 
Bulletin No. 337. 



40 

Teiser: What was the period in which you worked on the olives in 
this particular experiment? 

Cruess: I think it was around 1920. 

Teiser: You continued working with olives after you solved that one, 
did you not? 

Cruess: Yes. I ve given more attention to olives than to any other 
fruit, and I m still working on them although last year 
and this year I did not and will not do very much work on 
the olive. Back in 1933 and 1934 we worked with the Cali 
fornia Olive Association, and they established a big meeting 
that is held once a year. They have been meeting for the 
last forty-five years. Everything that has been done on 
research into the canning of olives was reported to the 
olive industry at those annual meetings. 

Teiser: They have had a closer organization than most growers. 

Cruess: Yes, they have. 

Teiser: What other types of research did you do on olives? 

Cruess: Oh, I d have to have the old publications to discuss that; 
but at least one per year for the last forty-five years. 

Teiser: All of your work is published, is it not? 

Cruess: Yes. 

Teiser: Ten or fifteen years ago you gave us some little cans of 
experimental olive products. You were working on ways of 
using excess or undergrade olives by mixing them with other 



41 

Teiser: things, I believe. Is that correct? 

Cruess: That was a ground up mixture of olives and greens, called 
olive relish. 

Teiser: It was good. 

Cruess: Several companies are making that type of product --chopped, 
canned olives. They use olives that are not quite good 
enough to be canned whole but can be canned chopped up or 
ground or minced. Probably twenty per cent of the olives 
do not have the natural flavor and may be soft in texture 
but are good for making chopped or ground up olives, known 
as chopped olives. 

Teiser: Who had the idea of marketing chopped olives? 

Cruess: Oh, I think the Bell Olive Company started it first. 

Teiser: Then the idea for that product didn t come from the Uni 
versity? 

Cruess: No, I don t think so. 

Teiser: Did you work on ways of handling the product here? 

Cruess: Yes, we have, but it was largely a commercial development. 

Teiser: Were the sliced olives commercially inspired? 

Cruess: No, I think we were the first to suggest that kind of product. 
One of our graduates was in the olive business. He has since 
died four or five years ago. His name was Richard Ball. He 
worked for the Pacific Olive Company, and he did quite a bit 
of development work on canning sliced olives. They have 



42 

Cruess: never taken on and become popular. The Pacific Olive 

Company, I think, still cans them, but the demand is not 
very great. The price has to be fairly high to cover the 
cost of pickling and canning, and apparently the people 
won t pay enough for such a product to make it worthwhile. 
The chopped olives can be used in much the same way as the 
sliced and can be made and canned much more cheaply. 

Teiser: I don t know how much nutritional value there is in chopped 
olives, but there is a lot of flavor for a small amount of 
money. 

Cruess: Yes, that s it. 

Teiser: Is there much nutritional value in ripe olives? 

Cruess: No, not very much. The oil content is the main nutritional 

value, because everything else is leached out in the pickling 
process. The flavor is largely due to the adding of salt, 
and of course salt is a very low priced product. 

Teiser: Is much oil retained in the canned product? 

Cruess: Yes, the oil is all retained. Green olives have, oh, ten 
per cent, whereas the olives that are used for the ripe 
process--the Mission olives--have twenty per cent oil. The 
chopped olives are made from two varieties that are quite 
rich in oil the Mission olive and the Manzanillo olive. 

Teiser: Is the Manzanillo the one that is also used here for green 
olives? 



43 
Cruess: Yes, it is used for green olives. It s smaller in size than 

the Sevillano. Sevillano has about fourteen per cent oil, 

and it s in demand for whole green olives or pitted green 

olives. 
Teiser: Pitting is one of the great revolutions in the industry 

here, isn t it? 
Cruess: Yes. The pitting was developed very largely by the Lindsay 

Ripe Olive Company. They were the ones, I think, who were 

the first to produce it commercially. 

Teiser: Did you do some work on different flavors for olives? 
Cruess: Yes. We tried various additions of ingredients, to the 

chopped olives especially, and also to the green olives, 

but it is not used very extensively because of the cost and 

returns. 



44 



PUBLICATIONS AND FOOD INDUSTRY ASSOCIATIONS 
(Interview 4, November 9, 1966) 

Cruess: I thought I would just call attention to some of my old 

publications. This book is the first of this series that 
I wrote. 

Teiser: These are all different editions of Commercial Fruit and 
Vegetable Products? 

Cruess: Yes, the fourth edition is the latest edition. 

Teiser: The first was published in 1924? 

Cruess: Yes. 

Teiser: I always wondered what sort of work went into such a great 
compilation of material. 

Cruess: I think it grew to considerable size due to the fact that we 
used it in teaching, that is, in the course I gave in the 
University. It was a lecture course on fruit and vegetable 
products, that is, the canning and drying and so forth. Each 
chapter was more or less a lecture, or two or three lectures 
in some cases. The information in this book was in my lectures, 
so the first edition didn t contain many illustrations and 
was quite short. In the fourth edition we put in even more 
illustrations. 

Teiser: Did you rewrite it each of these times? , 

Cruess: Yes. 



45 

Teiser: The fourth edition was published in 1958. 
Cruess: In the fourth edition, we rewrote it. The company wanted 

the size cut down because it was too long, so I think we 

abolished four chapters in making up the fourth edition. 
Teiser: Are you using the editorial we now? This is your book, 

is it not? 
Cruess: Yes. And here is the entire Olive Association history 

[a stack of publications]. It began in 1922. 

Teiser: It says Proceedings of the Olive Processors Conference. 
Cruess: The proceedings are published every year. 
Teiser: From 1922 on? 
Cruess: Yes. 

Teiser: The 1922 copy is small compared to the others, isn t it? 
Cruess: Yes. It contains a list of papers. 
Teiser: I suppose you have given papers at almost every one of the 

conferences. 
Cruess: Yes, I did. 
Teiser: Every one? 
Cruess: Yes, every one. Except that during the war the meetings were 

discontinued, although we did get together our papers and 

compile them in the Proceedings despite the fact that we 

didn t hold the meetings. 
Teiser: Were olives shipped overseas to the troops? Were they a 

Quartermaster General interest? 



46 
Cruess: I think they didn t make olives a special item, but they were 

included in overseas shipments to the troops. 
Teiser: Have the papers you have done on olives been in direct 

response to industry demand and need, or have you done some 

pure research too? 
Cruess: Most of the research has been in response to demands for 

solving of problems, but some of them were done just for 

the fun of it. 

Teiser: The "fun of it," is that what you call pure research? 
Cruess: Yes. Each one of these [Olive Association] papers is by 

various people. In most cases they are members of the Olive 

Association and are commercial men, but in some cases they 

are from the U. S. Department of Agriculture, the University, 

or the National Canners Association, that is, non-industry 

people. 
Teiser: It s a remarkable organization of growers and processors, 

isn t it? 
Cruess: Yes, it is fairly unique. I don t know of any other single 

industry that has been so faithful as we have been in getting 

up proceedings and so forth. 
Teiser: And meeting on technical problems? 
Cruess: Yes. The National Canners Association is, of course, 

nation-wide, and they cover a wider ground than we do. They 

have been going for many years now. 



47 

Teiser: You have given papers many times at meetings of the National 
Canners Association, have you not? 

Cruess: Not so many times, but I have several times. It costs quite 
a bit of money, and in those early days we didn t have money 
to travel, and it was too heavy an expense for me at first. 

Teiser: Weren t you given an award by the national Institute of 

Food Technologists? You have been given so many awards that 
I can t keep them all straight. 

Cruess: Yes. They gave me one several years ago. I have not 
attended their meetings very often because it was too 
expensive. 

Teiser: You have been quite close to the California Canners League, 
have you not? 

Cruess: Yes. I have gone to most of their meetings since about 1913, 
but the last two or three years I have not attended. The 
University doesn t participate in all their meetings. Once 
a year they have a meeting of the Canners League of Cali 
fornia, but usually most of the papers are either by members 
of the National Canners Association research staff or by 
industry people. We attend mostly for the information that 
we get. 

Teiser: Mostly to listen? 

Cruess: Yes, and to keep acquainted with men in the industry and to 
pick up some "three star" and so forth. 



48 

Teiser: [Laughter] They have good cocktails there. When you first 
knew the Canners 1 Association, was it a small organization? 

Cruess: Yes, it was small in those days. They had a national office 
in Washington and not a very large research staff. Way 
back in 1910 to 1915, they developed a technical staff. In 
the last twenty-five years they have built up quite a 
research staff in Washington D. C., Seattle, and in California. 

Teiser: This is the National Canners Association? 

Cruess: Yes, the N. C. A. 

Teiser: The California state association has had a fairly continuous 
history too, has it not? 

Cruess: In that case, the organization has been broken up according 
to the composition of the people in the industry. It is not 
a single organization like the National Canners. 

Teiser: Who sponsors the yearly cuttings? 

Cruess: That is done by the National Canners and also largely by 
the local associations. There is another association in 
addition to the National Canners: the Institute of Food 
Technologists, which is independent of the commercial canners. 
It is related to all of the industries which come under food 
legislation. It is independent of the National Canners and 
independent of the Olive Association and so on, but they have 
quite a wide ground to cover. 

Teiser: You have been active in the I. F. T. for many years, have 



49 
Teiser: you not? 

Cruess: I have been quite active in it. 

Teiser: Weren t you the recipient of their highest award, the Nicholas 
Appert award? 

Cruess: Yes, I had three or four awards from them. 

Teiser: I m looking at the item from Leaders in American Science, 
the fifth edition, the biographical entry on you. It says 
that you also recieved an award of merit form the Dried Fruit 
Association of California. Was that for a particular effort? 

Cruess: For many years we carried on research on the dehydration and 
sun drying of fruits, and we have participated for about the 
last forty years in their annual meetings. Sometimes we gave 
papers and sometimes we just attended. 

Teiser: Did you do extensive work with raisins? 

Cruess: Yes. During the period of Prohibition, the drying of fruits 
was our major field of research. We built a dehydrator at 
Davis, and Professor Arthur Christie and I gave much of our 
time to building and equipping it and using the dehydrator 
at Davis experimentally. Christie joined us in the 
department --and was in charge of the dehydrator. This led to 
an appointment for him with the Walnut Association. He left 
to join the Walnut Growers more than twenty-five years ago 
and became a key man with them. He retired about two years 
ago. He and I worked together within the University on 
dehydration. That preceded our work on wine. 




One of first judgings at California State Fair 

at Sacramento about 1936 

Standing, left to right: Louis Wetmore, in charge of orchards in San Joaquin 
Valley for Libby, McNeill, and Libby; Maynard A. Joslyn, Assistant Professor at 
Berkeley; William V. Cruess, Professor at Berkeley; Maynard A. Amerine, 
Instructor at Davis. Seated, left to right: George L. Marsh, Associate at 
Berkeley; Albert J. Winkler, Professor at Davis. 



50 



WORK WITH WINE FOLLOWING REPEAL 

Cruess: The wine making wasn t anything that I had planned 
to take up again. I started with wine research way back in 
1911 and through 1918 spent most of my research time on wine 
making. Then when the fermentation industries were revived 
after the repeal of Prohibition, there was a tremendous 
amount of work that had to be done to teach and show the wine 
people how to make wine without losing it. The first year 
or two they made a lot of vinegar instead of wine. [Laughter] 
With the development of the fermentation work at Davis, I 
gradually moved out of wine research and haven t done much of 
it in the last ten years or so. 

Teiser: It was my impression that your work with the wine industry 
just after Repeal was a very important factor in re-estab 
lishing it on a quality basis. 

Cruess: Yes, I think it was. There were several graduate students at 
that time, and we used them to carry on wine research. We 
didn t have very much money, and they had to spend about half 
their time on graduate research for higher degrees. Two of 
them got Doctor s degrees Dr. Mrak and Dr. Joslyn. They 
started as graduate students, and we didn t have enough money 
to get them appointed to better positions, but it was hard 



51 

Cruess: times, and they were willing to work without very much pay. 

Teiser: Part of the work was research and part of it was carrying 
results of the research and earlier knowledge to the wine 
growers, was it not? 

Cruess: Yes. As for as wine making was concerned, all of us spent 
a great deal of our time visiting the various wineries and 
holding wine meetings and so on to educate the wine makers. 

Teiser: Did you go to them, or did they come to you? 

Cruess: It was a little of both, but mostly we went to them and 

held meetings. We would present several papers in a one- 
day meeting. We had meetings in both Napa and Sonoma several 
times. And we went down to Southern California on several 
occasions, since there were big wineries around San Bernar 
dino and mainly around Cucamonga. They were usually the big 
wineries that knew pretty well how to make wine, because they 
had been making and experimenting with grapes and wine as 
much as they could during Prohibition. Quite a lot of wine 
went to the Catholic missions and churches. 

Teiser: I guess we owe a great debt to the church, don t we? 

Cruess: Yes, I guess we do, which is a hard thing for a Presbyterian 
to say. [Laughter] 

Teiser: Concerning the Southern California wine makers I ve always 

been curious to know whether it is the conditions in Southern 
California or their techniques that make their wine presumably 



52 

Teiser: less fine than the best of northern California wines. 
Cruess: I think it is the high temperature of the hot summers which 

make for quantity but not quality. Most of their wine is 

low in acid. They have too high a temperature to grow wines 

of high table wine quality. 
Teiser: Were there a few men who stood out as leaders in the revival of 

the industry after Repeal? 
Cruess: Yes. There were a few, like Louis M. Martini, Frank Swett, 

Arthur Lachman, Charles Wetmore, and Colonel A. Haraszthy. 

E. M. Sheehan was in charge of promoting the wine industry. 

He was head of the State Viticulture Commissioners N. V. C. 
Teiser: Were there some young men who suddenly got excited about the 

wine industry in that period? 
Cruess: Yes, I think there were quite a few. 

Teiser: Were they the young men who came to Davis to take courses? 
Cruess: Several of them were. Several of them also were entirely 

new to the wine industry. During that period they were not 

very prosperous, and there were not very many jobs in the 

wine industry. 
Teiser: Did some of the wine makers actually come to the University 

to take courses just after Repeal? 
Cruess: Yes. During the first two or three years we had extension 

courses on wine making both here and at some of the wine 

making centers. 



53 

Teiser: Did you give some of those courses yourself? 

Cruess: Yes. If they were not exactly courses, they were meetings at 
which several of the University profs and several of the 
industry men gave papers and held discussions. We did a 
large amount of Extension work. We worked quite closely with 
the Extension people of the University. They would arrange 
for meetings. I won t call them courses because they were not 
exactly courses but rather Extension Service meetings. 

Teiser: Were there several others in the department who were active 
with you in the post-Repeal period? 

Cruess: Yes. These young fellows who had never done any research 
on wines--about all they knew about wine was how to use it 
proper ly--and among them were [Emil] Mrak, who is now 
chancellor at Davis, and [Maynard A.] Joslyn, who is now in 
nutrition. There was a young man who did a lot of work on 
the chemistry of wine making [L. G.] Saywell. He left the 
University about thirty years ago, I guess. I think there 
were four of us who worked together for about four or five 
years. Saywell shortly went to work for a large company, 
and reputedly he has made considerable money. He left the 
University two or three years after he graduated. 

Teiser: You were the one who had the knowledge that was carried 
over from the earlier period, were you not? 

Cruess: Yes. I gave them all I knew, and they read a lot. 



54 

Cruess: I followed the research very closely. 

Teiser: A friend of mine at Stanford University said that you had 
developed cultures for specific California wines, like 
Louis Martini s Moscato Amabile. 

Cruess: I had worked with that experimentally, but what I developed 
was not that, but the yeast for the Spanish flor sherry. I 
didn t discover it, of course. It was discovered and devel 
oped in Spain a long time ago, but that particular wine was 
not made in California and never occurred here naturally. 
We have thousands and thousands of wines that occur naturally, 
but none of them were of the Spanish sherry type. I got 
cultures of the Spanish sherry from various sources in 
Europe and made pure cultures. I studied them and developed 
a method. These Spanish sherries are now present all through 
the California wine industry. They have caused some trouble; 
that is, they are fine for making Spanish sherry, but they 
also cause a little clouding in other wines if they are not 
held in check. So the wine makers know that now and do not 
allow the flor yeast to contaminate other wines. The flor 
yeasts are good and desirable for the flor sherry, but they 
are a pain in the neck if they grow in other wines. 

Teiser: Have you worked with Louis Martini on yeast cultures for 
the Moscato Amabile? 

Cruess: Louis Martini, Jr. was one of my students, and I knew him 



55 

Cruess: well. The wine that he used was a well-known wine made 

from California grapes and not a wine that I developed. He 
made a culture of flor yeast and increased its development and 
use . 

Teiser: You did some work on very low alcoholic content wines and 
also on very high alcoholic content wines? 

Cruess: Yes, I did. In 1919, when the country was dry and it was 
against the law to make wine, we worked on a process of 
making high alcohol content wines--eighteen or nineteen 
per cent alcohol. We published some of our findings. One 
of my students and I worked on it , I think, in 1919; he has 
since passed away. That was on the high alcohol content 
wines. There wasn t much demand at that time for wines 
with an eighteen or nineteen per cent alcohol content, 
because it was against the law everywhere in the United 
States to make wine. But I had a student that had to have 
a problem to work on, so he worked on the making of high 
alcohol content wines by fermentation. Ordinarily, the high 
alcohol content that is necessary for sherry and port and so 
forth the dessert wines is acquired by adding brandy or 
alcohol. We were able to produce them by fermentation. That 
is just of academic interest, because under the alcohol 
regulations, to make a wine with that alcohol content you 
have to add brandy and pay for the alcohol that you use. 



56 

Teiser: Should the law be changed? 

Cruess: No, I don t think so. It is rather difficult to use it, 

and if it is not used properly, you wind up making vinegar 
and more or less non-usable products. So the process is 
not used commercially, and the brandy regulations more or 
less prevent its use anyway. 

Perhaps I should mention another word or two about 
Louis Martini, Sr. He if the father of my student, who is 
also Louis. He [the father] is a graduate of an enological 
school in Italy and founder of the L. M. Martini winery of 
California and still very active. 



57 



FURTHER ON OLIVE RESEARCHES 

Cruess: I thought I might give a summary of some of the olive 

research work. One of the pieces of early olive research 
was on the nature of the bitter principle. I took that as 
a problem to study for my Doctor s degree at Stanford. The 
bitter principle is quite interesting. A glucocide chemical 
can be hydrolized with sodium hydroxide, and from that you 
get a series of chemical compounds that are used for studying 
the chemistry of the olive. That was one of the reasons 
that I have always been interested in experiments on olive 
research. 

Teiser: Stanford was an unusual place to work on such a practical 
project, was it not? 

Cruess: Yes, it was. Most of my work was done with Dr. Alsberg in the 
chemistry department at Stanford. He later transferred to 
California. About twenty years ago he overdid and suffered 
a case of pneumonia and died. 

The chemistry of the bitter principle is known as 
oleuropein. It was really my excuse for doing some graduate 
work at Stanford. But I became interested in it and remained 
interested ever since. It led to experiments in various 
other fields, such as on quick methods of pickling. At that 



58 

Cruess: time it took about three weeks to pickle olives by the ripe 
process; it was very slow. In our experiments we were able 
to cut down the time to two or three days. In speeding up 
so much, cutting the process down to three days, the quality 
of the pickled product is not so high. As a matter of course 
in commercial practice now, they use a six or seven day 
method. Some of the olive men themselves were able to shorten 
the process very much. If you use just a moderately warm 
temperature, the olives are apt to spoil. But by using a 
temperature high enough to destroy micro-organisms and cut 
down enzyme action, just long enough to bring about these 
changes, you can cut the process very materially. 

A very important feature of the process of pickling 
ripe olives is to darken the skin and to destroy the bitter 
principle. Then they are placed in water for a couple of 
days or longer. During that period, they may be aerated. 
The usual process for blackening the color, to get the black 
color that is demanded in ripe olives, is by exposure of the 
olives to air. The second method, the one which is now used 
more commonly, is to aerate the water in which the olives 
are held. A number of our experiments and research were on 
methods of controlling the darkening process by using a high 
enough temperature to inactivate the enzymes. We found that by 
pasteurizing or heating the olives to about 180 F., the enzymes 



59 

Cruess: would be inactivated and the pickling process would continue. 
I might say that twenty-five years ago, a large percentage 
of the olives were spoiled by bacterial action during 
pickling and had to be thrown away. There was one company in 
the south that went out of business because such a large 
percentage of their crop was spoiled. We found that the 
spoilage was bacterial. The secret of avoiding spoilage 
was to use a high enough temperature to kill the bacteria 
that were responsible for the spoilage. So twenty-five years 
ago an owner called me up and said that he would have to go 
out of business unless he could prevent spoilage of his olives 
during washing. I went down the next day to his place in 
southern California and found, as I knew beforehand, that 
we could control the spoilage by using a high enough tempera 
ture to destroy the bacteria that were causing the spoilage. 
We tried that in a small way at the factory, and it seemed to 
work. So the next morning the foreman had machinery put in 
to apply our methods of prevention of bacteria spoilage. So 
within a period of a week or so he was able to completely 
eradicate the spoilage, and the process was soon applied in 
the other plants. It was sort of an underground method of 
transmitting information from one place to another and from 
one plant to another. The method of preventing spoilage was 
soon known and used very extensively, so that that kind of 



60 

Cruess: spoilage was prevented completely and has never caused any 
further trouble. 

Teiser: What olive company was that? 

Cruess: It was a Long Beach company which has since gone out of 

business, but not for spoilage reasons. The owner, I think, 
was sidetracked by his interest in "another gal." He died 
about twenty years ago. He had a factory in southern 
California, but when he went bust, they closed up the plant. 

One of the most important changes that we made in 
the pickling process was the use of cans that were coated 
inside. They were called enamel lined cans. They of course 
were not new; they had been used for some fruits for twenty 
years or so before. But so far as ripe olives were concerned, 
they were canned at that time in plain tin cans. The olives 
during pickling would turn black, which was the desirable 
color. But on standing after sterilization in the plain tin 
can, they gradually deteriorated in color. They gradually 
bleached out until after three or four or five or six months, 
they bleached so much in color that they were not so much in 
demand. We found that if they were sterilized in cans that 
were enamel lined, the olives would hold their color indef 
initely. I ve seen olives still with good color ten years 
after canning. 

Teiser: Did you do some work in this area? 



61 

Cruess: Yes. I didn t do any work with making or coating the cans, 
but I used the enamel lined coated cans for experiments. 
The color was preserved by this method of canning. 
Teiser: Whose suggestion was it that enamel lined cans be tried? 
Cruess: I think I was the one who suggested it originally, but some 

of the commercial can makers had the same idea. We were just 
a little ahead of them. 

Another problem when we first took up sterilization 
of cans after the famous botulinus poisoning incident. That 
was just a few years after they started canning olives. They 
were using the temperature of the boiling point of water to 
sterilize the olives, which wasn t enough, and botulinus 
bacteria survived that temperature. That was not settled 
until about 1921. But the olives previous to that time had 
been pasteurized at a temperature not high enough to kill the 
bacteria botulinus but high enough to keep the product. But 
when it came to use the very high temperatures necessary to 
kill botulinus, many of the olives softened, and it was found 
due to the residual lye left during the pickling. That is, 
the olives contained a trace of the lye used in pickling. Or 
the pickling process had affected the texture of the olives 
so that the heat--the flesh that has been under the pickling 
process is sensitive to a high temperature and will soften. 
But if the pickling process can be carried on without leaving 



62 

Cruess: any lye in the tissues, the olives do not soften, and they 

then stand up very well. Our early work after the change from 
the low temperature of 150 to 160 F. to a temperature of 
250 F. caused the softening of the olives. By changing the 
pickling method just slightly so that there was no excess, no 
trace of lye, the olives did not change in texture. 

Teiser: Was this your guess that this might work? 

Cruess: Yes. Dr. Meyer and other bacteriologists were working on 

the poisoning, and sterilization. We didn t want to work on 
the bacteria spoilage, because that involved the health 
feature of the preservation of food, and that was, of course, 
under the State Board of Health. Our job was to find ways of 
having canned olives of the proper texture and flavor, so 
that people would buy and use them. We didn t work at all 
with the poisons. 

Teiser: Who suspected that the residual lye was causing the softening? 

Cruess: I think that was ourselves. 

Teiser: Is that you individually? 

Cruess: Yes. I and some of the men from the University who were 

working on olives. So you might say that was control of the pH 
value of olives during sterilization. When olives are 
sterilized at a high temperature, it is called retorting 
using heat and pressure. 

Teiser: This was an instance in which the University through you 



63 

Teiser: definitely saved an industry, wasn t it? 

Cruess: It improved the final product, but it probably would have 
been done anyway. 

Teiser: It would have been done by someone else if you hadn t done 

it, but you did. I think it is interesting how the division 
and department of Food Technology has served this very 
definite dual purpose of teaching and working with the 
growers and processors. I don t know if there are other 
departments in the University which have had such a strong 
dual function. 

Cruess: There is the mining industry, of course. 

We did considerable work on the Spanish green 
process of pickling olives. And in order to know something 
about it, I took some of my sabbatical leave in 1922-1923 
to spend time in Spain. The wife and I actually lived for 
two months in Spain. I got a lot of information on the green 
olive pickling process, and it was sufficient to advise the 
processors and packers of canned olives on how to do it 
successfully. At that time, there was only one company that 
was pickling olives by the Spanish process, and they had 
some difficulty with it. We made available to them the results 
of our research on pickling green olives, and they carried 
them on after that for several years, actual pickling and 
packing green olives in commercial quantities, in Visalia 



64 

Cruess: in the south, and Oroville in the north. Now, the pickling 
of green olives is carried on at most commercial olive 
canneries as a means of utilizing the small fruit. For us, 
it was an extension of the pickling and packing of green 
olives in Spain, adapting their methods to California 
conditions. 

Dr. Vaughn is carrying on that phase of the work, 
and he has two or three men involved in Ph.D. research in 
this area. Olives can spoil in so many different ways, and 
it is quite an expensive spoilage. Olives are a high-priced 
commodity, and if you lose a cask of green olives by spoilage, 
it amounts to quite a bit of money. So there is still quite 
a demand for research on green olive pickling. Although I 
started pickling green olives twenty or twenty-five years 
ago, Dr. Vaughn has kept it up and has published several 
papers on it. There is quite a demand for research by the 
olive association, and he published articles in the Proceedings, 
So the Spanish green olives have become quite important 
commercially. Much of the experimental work has been done by 
Dr. Vaughn and others, and his students. 

One of the most important experiments came right 
after our visit to the Spanish green pickling plants. That 
was on incubation. That is, Spain has a warmer climate that 
we have, and they ship their olives soon after pickling. 



65 

Cruess: The voyage is slow, and the olives continue curing and 

pickling right in the casks. By the time they reach the market 
they are cured. So without doing very much research on it, 
it was obvious that the green olives reached the market in 
good condition. But when the process was applied to Cali 
fornia, by the time green olives are pickled, it has turned 
coldtoo cold for them to go on pickling. For that reason, 
the pickling was slow and the olives were not ready to be 
sold until the following summer. So the problem was to 
shorten the process. The obvious answer was to incubate the 
olives, to keep them warm so they would continue to undergo 
curing. That was the principal change that we made in the 
green olive process. It was something that they didn t 
have to bother with in Spain because it was warm and the 
olives went on curing. But in California the temperature 
was lower, and they found that they should incubate them. 
The second problem was the lack of sugar in the 
Spanish olives. Most of the sugar was washed out during the 
pickling process that was used at that time, so that they 
didn t develop enough acid by natural pickling but only by 
adding sugar. Sugar is necessary to form acid by the lactic 
acid bacteria, and lactic acid is necessary to lower the pH 
level, that is, to increase the acidity sufficiently for the 
product to have a flavor of pickled green olives. So one of 



66 

Cruess: the main changes we made in the pickling process of green 
olives was to add a little sugar several times during the 
fermentation. Another thing we did was raise the temperature, 
that is, incubate them, but incubation will soon use up all 
the sugar. So, in addition to incubation, we added small 
amounts of sugar. If you add too much sugar, it will spoil 
the olives, so it is a matter of adding just the right 
amount . 

The first work that I did on olive pickling was 
done way back in 1915, I think. The main purpose of our 
experiments then was to shorten the process. It usually took 
about three months for the fermentation to be complete. 

Professor Bioletti arranged for me to carry on 
experiments on pickling of ripe olives with a cannery in 
Hayward , the Hunt Brothers Cannery. We found that it was 
possible to shorten the process from three weeks down to 
three days by raising the temperature and by pumping air 
through the olives. Using a higher temperature, and 
pumping air through the olives at the same time, that 
combination made it possible to shorten the process from 
three weeks down to three days. That combination was more or 
less new. If it is not properly made, the quality may be 
below that it should be, so the short process is not used 
very often, but we demonstrated that it is possible to shorten 



67 

Cruess: the process greatly. One of our graduates who is now working 
with the olive industry has cut the time down to one day, 
but his process is not used industrially. Bringing it down 
to five or six days is practical. 



68 



FROZEN FOODS 

(Interview 5, November 16, 1966) 

Teiser: What subject would you like to discuss today? 

Cruess: I have suggested the subject of frozen foods. The topic 

I have here [on card outline] is the history of the frozen 
foods in California. Back around 1925 there was almost no 
frozen food in retail packages. There were commercial plants 
for frozen meats and frozen fish. You could not buy them 
at retail except to take home and use [immediately] at the 
time. There were no frozen food cabinets in grocery stores. 
That took place about forty- five years ago and was one of 
our major lines of investigation. I think we started about 
1925, not systematically. Dr. E. L. Overholser of the 
pomology department had a freezing plant for experimental 
purposes. He later went to one of the other experiment 
stations, the one in Washington State. He started in 
California with the Pomology Department. He supervised the 
building and equipping of a plant for experimental cold 
storage work. I joined him, in another department, because 
he had the information and equipment. Later he went to the 
Experiment Station for Agriculture near Pullman, [Washington] , 
not the one in Seattle. He went there after he left Cali 
fornia. I worked with him from 1925 to 1930 or so, and we 



69 

Cruess: published a bulletin* on the freezing of fruits. It was not 
so very new except that we advocated or suggested freezing 
fruits in cans or closed containers, whereas before then 
fruits and vegetables and meats were stored in large 
containers or just in ordinary packages wrapped in paper. 
Our work was experimental in the use of small containers 
like glass jars and cans that could be used in the home or 
distributed through ordinary retail outlets. 

Since then, of course, frozen foods have been 
made available in packages in all retail stores. We carried 
on quite a few experiments between, oh, 1930 to 1940, but 
many others were working on the same problem, so we do not 
claim to be the first or the major ones in the development 
of frozen packages. We have meetings once a year with all 
the canning companies and freezing plants and so on, and 
with them for about five years we had displays of various 
frozen fruits and vegetables, in the displays of regular 
canned fruits and vegetables. These products that were 
preserved by heat or by sterilization were displayed beside 
our experimental packs, and we showed how much better the 



*W. V. Cruess, E. L. Overholser and S. A. Bjarnason, 
"Storage of Perishable Fruits at Freezing Temperatures." 

California Fruit News 64, (1724), July, 1921. 

(Not listed in W. V. Cruess Bibliography.) 



70 
Cruess: frozen foods were than the canned insofar as fresh flavor 

and appearance were concerned. But the canners of California, 
of course, were not very much interested in the frozen pack. 
Their business was canning and the sale of canned products. 
So our work, although it showed them what could be done, 
they didn t do it. Later on, some of the commercial cold 
storage plants not only in California but throughout the 
world became interested. We don t claim very much origin 
ality on the use of frozen fruits, but we carried on quite a 
few experiments, as I say, from 1925 to the present day, when 
we carry on investigations at Davis on frozen foods. But 
shortly after, it was demonstrated that frozen foods were 
vastly superior to the brined and canned in freshness of 
flavor and appearance. We don t say they were better, of 
course, but the frozen foods were different, and it was a 
means of giving the consumer or the housewife products that 
were of frozen quality and flavor. So now almost every 
food store in the country has frozen food cabinets for 
displaying and selling all kinds of things all the way from 
frozen fish and meats up to frozen vegetables and fruit juices, 
Teiser: Did you do some work on frozen orange juice? 
Cruess: Yes. Professor Joslyn did most of our work on frozen fruits, 
and for many years he carried on investigations of frozen 
orange juice. For example, he found that orange juice should 



71 
Cruess: be heated sufficiently before it is packed and frozen to 

inactivate certain enzymes, the ones that cause clouding 
and changes in flavor and so on. But the major breakthrough 
was accomplished by the experimental station in Florida-- 
the Florida Citrus Exchange. They found something that no 
one else had discovered, namely, when orange juice is frozen 
and thawed, ordinarily it doesn t have much flavor. But 
they found that if some of the juice were concentrated to 
about fifty-five per cent dissolved solids and that mixed 
with a moderate amount of fresh juice, it resulted in a good 
product. The mixed juice is frozen at about forty-five 
per cent soluble solids, and it is packed at about forty-five 
per cent. What we buy in ordinary retail stores contains 
forty-five per cent soluble solids. That has a fresh flavor 
from the addition of fresh juice, whereas the juice that is 
concentrated forty-five per cent has no fresh flavor. The 
flavor goes out in the concentrating process. Before it 
is frozen some fresh juice is added to impart a fresh taste. 
Before use, it is blended with fresh juice and concentrate 
containing fresh juice. 

Teiser: Did you do some work on this yourself? 

Cruess: I worked on the whole problem way back before they developed 
the present frozen orange methods. 

Teiser: They could hardly have arrived at the final technique 



72 

Teiser: without the basic, could they? 

Cruess: No. 

Teiser: I am trying to give you more credit than you are giving 
yourself. 

Cruess: I did some work on one thing that our department did, but 
most of it was done by Joslyn and [George L.] Marsh. We 
also found that if we froze ordinary navel orange juice, 
it would turn bitter, whereas the Valencia orange juice would 
retain its flavor and not change. So the principal thing 
that our department found was that the ordinary Valencia 
orange juice retained its flavor during freezing and thawing. 
The navel juice, upon freezing and thawing, turns bitter. 
For that reason, they haven t used the navel juice for 
frozen packing. No one has solved the problem of concentrating 
navel juice so that it won t become bitter. In that major 
piece of work that we did, I think Joslyn and others in our 
department, and I too, to a limited extent, discovered that 
it became quite bitter. It wasn t very much to discover, 
because almost everybody found that to take place. They 
packed a lot of the navel juice. 

California, naturally, had navel oranges, whereas 
the growers down in Florida didn t have the navel variety. 
They mostly grow some ten or eleven other varieties, none 
of which has the disagreeable flavor of the navel orange 



73 
Cruess: when frozen. But they all have trouble with the curdling 

of frozen food when it is thawed, unless the enzyme pectinase 
or pectic enzyme is inactivated by heat. We did the first 
work on that, and we found that heating to a sufficient 
temperature would inactivate those enzymes, and the juice 
would not curdle. The frozen pack orange juice now on the 
market doesn t have very much of the curdling trouble 
because of that discovery. I think that was one of the 
major findings. 

The orange juice that I mentioned previously was 
developed by Florida industry and largely by the men in the 
industry, U. S. D. A., the U. S. Department of Agriculture. 
They and the Florida Citrus Exchange research people found 
that the flavor could be retained by packing a mixture 
concentrated with enough of the fresh juice to give flavor 
to the mixture, as I said before. That was a very big 
finding, and it resulted in a tremendous increase in frozen 
citrus juices. Before that, a moderate amount of orange 
juice was frozen in cans, but it didn t have very much flavor. 
The Florida Exchange method of concentrating part of the 
juice and then adding fresh juice--the mixture was excellent 
in flavor and more or less like the fresh juice. 

Quite a bit of our work on frozen pack was done by 
Joslyn and Marsh on a grant from manufacturers, one of them for 



74 
Cruess: freezing equipment. They did a lot of work on rate of 

freezing, how long it took to thaw, and the changes that 
took place in freezing and thawing. Their findings were 
published by the University and the frozen food companies. 
But I personally didn t do very much on those experiments 
except to apply them and obtain funds for Joslyn and Marsh. 
Teiser: Were you head of the department at that time? 
Cruess: Yes. We have done a great deal on the practical problems 
of freezing, thawing, and packing of frozen fruits and 
vegetables. One thing that I and several others discovered 
was that if vegetables are frozen and then thawed, they 
acquire a disagreeable flavor, that is, if they are not 
blanched, if they are not thoroughly precooked before 
freezing. They will, after several weeks or months of 
freezing storage and then thawing, have a flavor so dis 
agreeable that people won t eat them. We discovered that 
if they were blanched or parboiled sufficiently, they 
could be frozen and kept for several years or as long as you 
wished without a change in flavor. That discovery was 
basic to the production of frozen vegetables. Frozen 
fruits retain their flavor without this method, but vege 
tables are quite different and will have a disagreeable 
flavor upon thawing if they have not been blanched suffic 
iently to inactivate the enzymes. However, that was also 



75 

Cruess: discovered by a man in the eastern United States at about the 
same time we discovered it. We claimed credit for it, but 
we are not sure he didn t beat us to it, although I think 
we did beat him to it. 

Teiser: Was that Clarence Birdseye? 

Cruess: Yes, it was Dr. D. K. Tressler, a man who has worked with 
Birdseye quite a bit. 

Teiser: The Birdseye Company publicity gave Birdseye a lot of the 
credit. 

Cruess: Yes, it did. He did more than anybody else to popularize 
and increase the use of frozen pack vegetables. I knew 
him quite well; he always used to stop by when he came 
through this area. 

Teiser: Was he a nice fellow? 

Cruess: Yes. He died about five or so years ago. He was a good 

sort. He was strong on patenting everything, and he did so. 
So the Birdseye process is very thoroughly patented. 
Everything that they did was patented, so it s well protected. 

Teiser: Were there basic things that were patentable in the freezing 
process? 

Cruess: Quite a bit of our research was on the changes that take 

place during freezing and thawing rather than on devising new 
methods or equipment. Part of our work was on what happens, 
and to some extent on new methods. For example, the frozen 



76 

Cruess: pack of dry sugar instead of syrup with berries was worked 
on in our department, although it was developed more by 
industry than by us. 

Although it s not very important commercially, 
Joslyn and I developed a method of preparing and freezing 
avocados. They should be sieved, or made into small pieces. 
And persimmons should be dead ripe and then sieved. Those 
two products can be made commercially, but they are not, 
because they are so much in demand for fresh use. 

People in the Hawaiian Islands have done a lot of 
work on frozen tropical fruits such as the avocado. And 
the guava, which is peeled, cut in peices, and packed in 
juice or in syrup. Another fruit, the papaya, has been 
packed commercially in the Islands. The lower grades, 
not perfect fruit, are cut, sliced, and packed with syrup 
or mixed with other fruits, and frozen or preserved by 
pasteurization and so forth. The mango can be frozen as a 
purSe and is a very nice product, but the demand for fresh 
fruit is so great that there is no reason for packing it. 
The second quality of papayas doesn t appear attractive enough 
to sell as fresh fruit but can be used to produce by-products. 
The volume is not very great, and I do not think that any 
of the papaya products are on the market. But papaya juice 
and papaya syrup and papaya concentrate and mixed papaya 



77 
Cruess: and other fruits can be packed in syrup. 

We did quite a bit of work on the retention of the 
color and flavor of fresh sliced fruits. We observed and 
found that a small amount of sulphur dioxide, SO- , packed 
with the syrup or with the sliced fruit, tended to hold the 
color and flavor of sliced peaches and sliced pears and other 
sliced fruits. A small amount of sulphur dioxide, not enough 
to make the flavor disagreeable, but enough to hold the 
color, was very useful. It is used commercially for 
frozen, sliced fruit, for baking and so forth, but it 
is not used so much for retail packages because they don t 
require much of it. So I think all that need be said about 
the use of sulphur dioxide is that it is used for sliced 
fruit, particularly peaches, apricots, and pears, to hold 
their color and flavor. Commercially it isn t used very 
much [for retail packages] because it takes a lot of extra 
work to add it. The commercial plants that freeze these 
products, sliced peaches especially, and apricots, do it 
in such a large volume that it can be done economically, 
whereas in the small retail packages it is not so practical 
to add the sulphur dioxide. 

Ripe olives can be frozen, but there isn t much 
demand for that because they are just about as good canned and 
sterilized by heat as they are frozen. But our experiments 



78 

Cruess: showed that ripe olives could be packed with a dilute brine 
and frozen and would be pleasing in texture and flavor upon 
thawing. So if there were much demand for frozen olives, 
they could be packed. 

Teiser: Would that be more economical than canning? 

Cruess: No, it wouldn t be as economical as canning, but the flavor 

might be superior, because the product is not canned by heat. 
It is just pickled and put in a dilute brine and preserved 
by freezing, so the flavor is that of the freshly pickled 
olive. But the unfortunate thing is that although the olives 
retain their flavor and texture through freezing and thawing, 
they soften quite a bit. The soft olive is not so attractive 
and is not very much in demand, so the frozen pack olives 
have not become commercially successful, although our 
experiments showed that it can be done. 

These are the reports of our experiments during the 
period dating from 1914 or 1915 up to the present time. They 
are the original typescripts for our various articles. They 
are articles that were copied by various publications. Many 
of these were just published and not put in a book. Most of 
them are in the bibliography of my published work. 

Teiser: You were the senior writer or the sole writer of most of 
them, were you not? 

Cruess: Yes. 



79 

Teiser: Are they copies that may be deposited in the Library? 
Cruess: Yes. They are copies of most of our publications up to the 

time I retired. It doesn t include the very few that came 

* 
out after I retired. 



* The collected papers of William V. Cruess are on deposit 
in the University Archives. 



80 



DEHYDRATION OF FRUITS AND NUTS 
(Interview 6, December 7, 1966) 

Cruess: I thought we might talk about the work that we did during 
1920 when we had an early rain, and practically all of the 
prunes that were dried in San Jose and the neighboring 
vicinity got moldy, and many of them spoiled. So many 
million dollars worth of prunes got vinegar sour and spoiled 
by the growth of yeast during the drying period. At that 
time most prunes were dried in the sun, and dehydration was 
not very much in use. Toward the end of September of 1920 
there was an early rain of about five or six inches. It 
rained on and off for a couple of weeks, so that the prunes 
grew whiskers and fermented and spoiled. 

We were called down there to run experiments to 
see if we could save some of the prunes and prevent this 
catastrophe again. So I spent about two weeks in San Jose 
in the drying yards. We found that the prunes, although 
they might be wet and developing a small amount of mold, 
some could be saved by treatment with sulphur dioxide fumes. 
So we saved a few of the prunes that way. They also had a 
few dehydrators, four or five when they should have had 
one hundred fifty or so. So they couldn t dehydrate many 
prunes, but they dehydrated a few of them, all they could, 



81 

Cruess: by the makeshift dryers. A few tons of prunes were saved 
in that way; some more were saved by the sulpher dioxide, 
sulphur fumes. 

As a result of the early rains of 1920, when so many 
prunes were lost, they designed dehydrators for that area. 
By the end of 1925 or so they had enough dehydrators so that 
if it rained early again, as it often did, they could save 
the prunes. Those experiments stimulated the building of 
dehydrators, so that within five or six years of the terrific 
spoilage by early rains, they built enough dehydrators to dry 
the entire crop. That catastrophe stimulated the prune 
growers to build enough dehydrators so that never again would 
they have to dry them in the sun. They dry a few in the sun 
but most of them in dehydrators, because they found that with 
dehydration the dried product was better in flavor and the 
yield was a little bit larger. So dehydration has replaced 
completely the drying of prunes in the sun except for a 
moderate amount of small dryers. 

There are a few small dryers left who couldn t 
afford or wouldn t build a dehydrator. For example, before 
I sold it [ranch] we used to have four or five prune trees, 
and the nearest dehydrator was ten miles away. So we dried 
that small amount in the sun. There are a few dryers 
scattered through the prune districts where sun-drying is 



82 

Cruess: still used on small orchards. But as a general rule, prunes 
are now dehydrated, whereas they were sun-dried before. As 
I said, our work on the rain damage stimulated the building 
of dehydrators for prunes. Professor A. W. Christie conducted 
a great deal of research on dehydration. He and I worked 
together on it.* 

Later they had the same problem with walnuts. 
Before then practically all of the walnuts were dried in the 
sun, but then they had rain damage losses. Walnuts usually 
are dried at a later date than prunes, but the late rains 
cause quite a lot of spoilage. Because of the experiments 
that Christie, who was one of my students, made, he was asked 
to join the Walnut Growers Association and carry on further 
experiments. He was hired by the Association after that. That 
was in 1928 or so, and he left the University and went to work 
for them. I didn t have very much to do with that. We had one 
student, Cliff Bedford, who was doing some work on the 
dehydration of walnuts, but most of the work was done by 
Christie, and the work was published in a bulletin. Several 
bulletins have been published since on the drying of walnuts. 



*See Bulletins 321, 322, 330, Circular 213, Proceedings of the 
First Dehydration Conference, and several other publications. 

W. V. C. 



83 

Cruess: He [Christie] went to work for the Association and got old 
enough to retire about two years ago. We have no one, I 
think, working on walnut dehydration at present except 
incidentally or occasionally. Practically one hundred 
per cent of the walnuts now are dried in dehydrators. 
Ordinarily prunes and other cut fruits are dehydrated at 
140 F. to 175 F., but walnuts will not stand that high 
temperature. They must be dried at not above 110 F., which 
Christie discovered. He got the growers to put in dehydrators 
and learn to operate them properly. So the dehydration 
experiments resulted in two very large advances in the 
building of dehydrators, namely the dehydration of prunes, 
grapes, apricots, pears, and peaches. 

Teiser: Do you remember what ranches you went to in the Santa Clara 
Valley when you first studied the problem in the 1920 s. 

Cruess: I worked with two associations; one was just east of San Jose 
and was known as the East Side Dryer. John Leonard and 
Anderson Barngrover Company were others. 

The work that we did on the sun-drying of prunes 
and the spoilage of prunes by early rains resulted in 
experiments on dehydration. And it also resulted in the 
building of an experimental dehydrator in Davis, California. 
Two years after the rain damage we had a dryer designed and 
built by Christie, Bioletti, myself, and others, and it 



84 

Cruess: was erected at Davis. Christie went to work for us between 
1915 and 1920, when we did so much work on dehydration and 
worked out the methods that should be used. For those years, 
about three years, during the drying of prunes and grapes 
and so forth, Christie or I, one or the other, spent all 
the time during the two or three months of drying of fruit, 
at Davis. We had a dryer that held about five tons of fruit, 
and we dried all kinds of fruits in various experimental ways. 
But prunes, peaches, grapes, and pears were used in many of 
our exp e r imen t s . 

We carried on quite a few experiments to work out 
the best method of preparing and drying the various fruits, 
expecially prunes, peaches, and grapes. For example, our 
dehydrator was so arranged that the temperature and the air 
flow could be varied. It was built in such a way that it 
would be run experimentally with a blast of air or air suction. 
As a result of the experiments that we made, dehydrators 
were improved, and the results were published. For example, 
one experiment was the drying of prunes on screen trays 
and also on wooden trays. On wooden trays, you have more 
sticking; the prunes dehydrate down and stick to the trays 
and are hard to get off. But most of the experiments on 
prunes were on other problems. 

Christie and I worked together with the carpenter 



85 

Cruess: and others at Davis on building the plant. Professor 

Bioletti, Christie, and I designed the dehydrator. It didn t 
have anything very unusual about it, but we tried to include 
equipment for varying the method of drying so that all possible 
conditions could be set up and experimented with. At that time 
the one who was not teaching for a day or two days lived at 
Davis and carried out dehydration experiments and directions 
for drying. 

Teiser: Did you maintain communal living quarters at Davis? 

Cruess: For dehydration, we had to be at the plant during the night, 
so one of us would go to bed about 8:30 p.m. and set the 
alarm to ring in an hour or so, when data could be taken 
on the amount of drying during that period and so forth. 
Once every hour and a half we had to wake up and go down to 
make a reading. There were the three of us. Professor 
Christie and I did most of the experimental work, but 
during the early afternoon, when neither one of us were 
available, Professor Flossfeder took care of the dehydration. 
He was interested in experimental drying of various fruits, 
especially grapes. He was a professor of viticulture. In 
that way, the three of us kept the thing going for a period of 
about three months. 

One of the experiments we did was on recirculation 
of the air for drying. If you dry fruit with a blast of air 



86 

Cruess: and throw the air away, two things happen. You waste a 
lot of heat and increase the cost to dry. But if you 
recirculate the air, pass the heated air around and around, 
you can cut down the loss by the carrying away of the hot 
air. It is simplest to say that the recirculation of the 
air used in drying was proven to be economical; that is, 
there was less loss of heat by recirculation and better 
control of the temperature of the drying. One of the things 
that Christie and I found was that by dehydration the yield 
was slightly increased, because the losses that would occur 
in sun-drying would be avoided so that a greater tonnage of 
fruit would be obtained by dehydration, controlled drying, 
than by sun-drying. Because in the sun, the fruit could go 
on metabolising. Sun-drying takes a couple of weeks, and 
during those weeks the fruit goes on metabolising or working 
so that some sugar is lost, and dehydration avoided that 
loss. So the cause of the lower yield by sun-drying was the 
loss of sugar, while the metabolism of the fruit was prevented 
by dehydration. The temperature was high enough so that the 
fruit didn t go on carrying on its metabolism. 

I mentioned that our experiments led to the 

dehydration of walnuts. That occurred right after the experi 
ments at Davis, and the experiments were continued by Professor 
Christie after he went to work for the Walnut Association. 



87 

Cruess: We had quite a large number of men working on 

dehydration and on sun-drying. They were usually advanced 
students that we got to help us with some of the experi 
ments. Nichols became the dehydration specialist. Nichols 
at that time was conducting dehydration research for the 
U. S. Department of Agriculture. He had done graduate 
research at Boston Tech and got an advanced degree there. 
Later he became a dehydration specialist for the U. S. D. A. 
in California. About the time that Christie was leaving 
for the Walnut Association we secured a position for Nichols 
in our department. He took over the research and teaching 
in dehydration in our department. He was a brilliant 
investigator and very fine person. He carried on in Christie s 
place. He was my right-hand man. A few years later he 
became ill with appendicitis, suffered complications, and 
suddenly died. That was a great blow to the department and 
a tragic loss to me personally. He was a "great guy." 

Reed was another one. In all, there were about 
fifteen in the laboratory, some of them students, some of 
them members of the staff, who helped us with the dehydration 
work. Christie was appointed by the Walnut Growers and was 
replaced by Nichols. 

One thing that we experimented on was what they 
call the parallel current method of dehydration. In that 



88 

Cruess: method, the freshly trayed fruit is put in at a very high 
temperature. That is, instead of 160 F. , at which 
temperature there is not much effect on the fruit, they 
used 200 F., a very high temperature. The rate of drying 
is thereby greatly increased. We didn t discover that, 
of course; it was done by C. C. Eidt, a Canadian specialist. 
The Canadian dehydrators did a lot of work on the parallel 
current method of drying. For the first few hours of drying 
you used a temperature near the boiling point, and the moisture 
was driven out very rapidly. But it couldn t be applied 
too long, because the fruit would get scorched and not be of 
a high enough quality for packing. So the initial part of 
dehydration is done at a very high temperature, 180-200 F. , 
and then finishing at a lower temperature so that there will 
not be scorch damage. We experimented with the Canadian 
process, which, by the way, is now quite often used for the 
dehydration of grapes and vegetables expecially. It s not 
very much used for other products. 

One measurement that we took was the effect of 
various temperatures of dehydration on the damage to the 
sugar in prunes and other fruits. Others had carried on 
investigations into the effect of high temperatures on the 
sugar content of fruit during drying. It was conducted by 
the Canadian workers and ourselves and others. It is now 



89 

Cruess: quite well established that a high temperature can be used 
when the fruit first goes into the dryer and until the 
fruit is about half dried. From there on, you have to get 
the temperature down low enough so the sugar is not destroyed 
and the product scorched. 

During the Second World War a lot of work was done 
on the dehydration of vegetables. Large quantities of dried 
vegetables were packed and delivered to the dehydrators of 
Great Britain. They did a lot of work during the period 
before America entered the war, and we have benefited by 
their experiments. As you might expect, since the dehydrators 
were built on short notice in many cases, many of them were 
not very efficient. It was found, for example, that if we 
tried to put the air through without guiding its flow, 
some of it would be lost. When the air went through properly, 
the fruit came out right. It was not realized at first that 
it was necessary to control the air flow so that the trays 
on the top of the stack of dryers did not get all the air 
and the trays at the bottom might not get any or got too 
little. In other words, there was very irregular air 
distribution. The problem was very easily solved by baffle 
plates and by so constructing the dehydrator that no air 
was lost at the bottom or at the top. Some might go above the 
trays and be lost, and some might be lost below the trays, 



90 
Cruess: so distribution of the air was very important. 

As I said before, we saved quite a few of the 
prunes that were rain damaged by sulphuring them. Of the 
many thosands of prunes, the growers only had facilities for 
a very small proportion of the crop. If sulphur was burned 
and the air containing a small amount of the burning sulphur 
fumes was passed around the damaged prunes, they could be 
saved. If the prunes that had suffered by too much water 
from the early rains those that were still edible could be 
saved if they were kept in the fumes of burning sulphur for 
two to three hours and then allowed to dry on the trays in 
the sun in the usual way. They would be edible although 
they would taste a little bit of sulphur dioxide. 

Most of the spoilage of rain-damaged fruit was 
caused by blue mold and by grey mold after the fruit was 
partly dried. I imagine that about ninety per cent or more 
of the prunes that were put on the trays at that time in 
September, 1920 to 1930, were so damaged that they were only 
good enough to be used for hog feed. That was quite an 
impetus for dehydration. 

The dehydrators for experimental dehydration at 
Davis were designed by, I think I mentioned before, Christie, 
Nichols, and others, but was done very much more thoroughly 
by engineers of the University in the department that was 



91 

Cruess: engaged in the construction and design of various equipment. 
They were useful to us in advising us how to design and build 
the dehydrator so that it would be efficient. So in addition 
to our own staff, members of the staff of Agricultural 
Engineering were very important in the design and construction 
and operation of the plant. They didn t work with us on the 
dehydration experiments, but they advised us a great deal on 
how to build an efficient dehydrator. 

I think I mentioned that a very important aspect of 
dehydration efficiency was the recirculation of air. The 
air could be blown through the fruit, and some of it could 
be sent back and used again. In that way the total amount of 
heat for dehydration was conserved and cut down. As much as 
seventy-five per cent of the air could be recirculated without 
damaging the fruit and would save fuel. 

In our experiments at Davis, most of the work was on 
prunes, but we also did a lot of work on the dehydration of 
grapes, peaches, apricots, and pears. The Thompson seedless 
grape is dried in the sun mostly, but a moderate quantity of 
the grapes are dehydrated. It is quite a tricky thing to 
dehydrate grapes without their sticking or being damaged by 
heat. They have to use a fairly low temperature of drying 
during the initial stage of dehydration, and various other 
factors have to be taken into account. Only a small amount 



92 

Cruess: of grapes are dehydrated; most of the raisins that you buy 
are dried in the sun. If you want to dry raisins that have 
a light color, they have to be dipped in dilute lye solution 
to check the skins and then dried on the trays with a modest 
amount of the fumes of burning sulphur sulphur dioxide 
passed through to hold the color. Nichols and I worked on 
the principles and methods of dehydration of grapes to make 
the light colored dehydrated raisins. But the amount used is 
moderate. 

Teiser: Did you and Dr. Nichols initially develop that technique? 

Cruess: No. Christie and I worked on the dehydration of grapes 

just to work out the best methods of accomplishing it. It 
was not discovered by ourselves; most of the work was done 
by commercial companies. One of the men who worked with us 
was Pucinelli. He was a young fellow, about twenty years old 
at that time, and he was quite interested in drying. He tried 
to build a little dehydrator in their prune orchard. We 
worked with him for a couple of years. Later he became so 
expert at it that he designed and built dehydrators as a means 
of making enough money to live. But as a result of experiments 
made in his orchard dehydrator, the best methods of handling 
prunes and grapes were worked out. Pucinelli helped us quite 
a bit at that time. Later he built dehydrators for other 
fruit growers in Sacramento Valley. Still later, and I think 



93 

Cruess: even now, he is building and operating dehydrators for 

grapes, prunes, and walnuts for the growers and the commercial 
plants. Incidentally, he has a dehydrating plant in Italy. 

Teiser: Are most of the grapes for dehydration grown around Fresno? 

Cruess: All of the prunes are grown at San Jose and around Sutter 

County in the Sacramento Valley. Sutter County grows a lot 
of prunes, and Sacramento Valley grows a lot. Also, many are 
grown and dried in the southern part of the Sacramento 
Valley. Above Sacramento, there are two or three valleys 
that grow prunes and grapes for dehydration, namely Napa and 
Sonoma Valleys. 

We spent a lot of time for three years and during the 
last days of World War II on the dehydration of vegetables. 



94 



DEHYDRATION OF VEGETABLES 
(Interview 7, December 15, 1966) 

Cruess: I thought I might start out this morning with a brief 

description or discussion of dehydration in World War I. 
We carried on some experiments at Berkeley and also at a 
large plant near Eureka, at Fortuna. The plant was used 
for dairy products: for butter preparation and packaging, 
and the dehydration of milk, dry milk, that is. We were 
invited at the beginning of World War I to use their plant as 
a place for the preservation and drying of vegetables 
experimentally. That was in 1918 and 1919. At that time 
vegetables were not dehydrated commercially, but we carried 
on experiments at this dairy products factory on blanching. 
We had noted that the dried products were very tough and of 
poor flavor. It was thought that by carrying on experiments 
on the precooking of the product and then drying it, the 
product would be of better flavor and texture when it was 
cooked, and that proved to be the case. Experiments were made, 
of course, in Germany and England, but the perfection of 
blanching for dehydration did not occur early enough to use 
that method of preparing the products for drying during 
World War I. Consequently, although the product made by 
slicing, dicing, or cutting the raw material into julienne 



95 

Cruess: strips and then drying looked very fine in appearance, but 
upon cooking they were tough and of very poor flavor. They 
could be cooked for one to two hours in live steam or boiling 
water and still be tough. At about that time World War I 
closed, and we carried on no more experiments at that time. 

But between World Wars I and II it was proven by 
the Germans and the English that the products should be 
precooked or blanched. That was done in Germany and England, 
and by the time we entered World War II it was a well 
established process. So our experiments on the preparation 
of vegetables for dehydration were quite simple as compared 
to World War I. In World War I, we blanched a lot in smaller 
quantities and worked out the processes of preparation and 
dehydration. But before that method was perfected and accepted, 
the need for dehydration in World War I was over. At the 
beginning of our participation in World War II the war had 
been going on for a couple of years by that timewe didn t 
have the facilities for large-scale experimentation, and again 
we went to the various commercial plants and conducted 
experiments on blanching. That was in 1941. 

During World War II they had the benefit of the 
perfection of preparation of vegetables for dehydration, 
especially in Germany. All of their products were blanched 
at that time, and the same thing was true in England. So 



96 

Cruess: the principal problem in America was the building of plants 
to get a sufficient amount of dehydrated vegetables to make 
it worthwhile. By dehydrating the precooked vegetables, you 
can carry from five to ten times the weight of dried as 
fresh vegetables. That was the reason for dehydration; to 
save time and space. For example, potatoes were washed 
very thoroughly in the spray washer. They were carried 
through a stream of water. They were then cut mechanically 
lengthwise into strips or across into sections. As you 
realize, potatoes have a large amount of soil and material 
that is not to be cooked, which clings to them, so they have 
to be washed very thoroughly. That is done by passing the 
potatoes through a spray of cold water, which usually removes 
or loosens all of the adhering soil. 

The product can then be put in the proper form for 
blanching. We found, and others have found also, that it 
was desirable to have some way of determining when the 
blanching was thorough or sufficient. If the potato or 
other vegetable is insufficiently blanched, it will remain 
tough and have a disagreeable odor, because it has the flavor 
of the raw product and has taken on changes in flavor that 
are undesirable. So if we use potatoes as an example, the 
potatoes are sliced and then put through another cutting 
machine that cuts them into narrow strips, that are about 



97 

Cruess: 1/16 of an inch in diameter and square in cross section. 
That form of vegetable is known as julienne strips. The 
potatoes, carrots, or whatever the product might be, are cut 
into julienne strips or into cubes or into slices. The 
blanching then consists of placing the strips, cubes, or 
whatever in a conveyor where they are steamed for a certain 
length of time. Usually vegetables like potatoes are carried 
through the conveyor, which is made of screen or strips, and 
travel through the steaming or blanching procedure. Potatoes 
take about six to seven minutes in live steam to finish the 
blanching process. 

Various methods are used to tell one when blanching 
is done. They blanch long enough so that the enzymes of the 
vegetables are destroyed. If the enzymes are not destroyed, 
the vegetable will then become tough and the flavor poor. 
The length of drying depends on the method of exposing the 
product to drying temperatures. Blanching was found to be 
necessary for all products except onions and garlic. If 
you stean onions and garlic to blanch them, you drive off the 
odor and taste. In the case of garlic, the flavored material 
is easily lost in dehydration, so they are not given a 
blanching process. They are cut into rather thin strips 
so that they dry quickly. They are dried at a temperature 
that is not high enough to drive off the flavor too much, 



98 

Cruess: usually 140 F. instead of the 160 F. or 165 F., which 
is used for other products. 

A very good indication of the adequacy of blanching 
is the absence of certain vitamins. That is, if they are 
blanched sufficiently, the carrots or potatoes or whatever 
are more or less free from peroxidase or vitamin C. The 
presence of these vitamins can be determined by putting a 
drop of indicator such as the enzyme ascorbase. You let 
it stand on the vegetable for about five or six minutes, 
and it will develop a reddish brown color with the indicator 
guaiacol, and that turns pink or red if the enzyme is still 
active or living. It usually takes three to five minutes in 
live steam to destroy the enzyme. If the product is cooked 
sufficiently before dehydration, the enzymes are usually 
inactivated. Two things are accompliched: the enzymes are 
inactivated, and the product is cooked sufficiently to be 
dried. The yellow color of carrot, carotene, is a good 
indicator of the adequacy of blanching. If the strips or 
slices are blanched sufficiently, they will show a negative 
test for the indicator. Benzidine, another indicator, 
turns pink when you place a drop of it on the blanched 
vegetable. If the vegetable or potato or other product is 
blanched sufficiently, on cooking it is tender and has a 
desirable flavor. Of course the products are usually soaked 



99 

Cruess: in water until they regain their original shape before they 
are cooked in the home. The prepared dehydrated potatoes 
or carrots, for example, are soaked in water overnight or 
for half an hour or so before they are cooked for the table. 
If the vegetables are not blanched, as was the case in 
World War I, they are so tough that they cannot be eaten, 
they wouldn t be very palatable. For that reason, more of 
the dehydrated vegetables in World War I were thrown away 
after they were cooked and put on the table than were used. 

In World War II the products had a good texture 
and a passable flavor, but all of the G.I. s whom I have 
talked with and who went through World War II never want 
to see, let alone taste, a dehydrated vegetable. The flavor 
is not bad, but it is quite flat, and the vegetables are 
lacking in vitamins. Carrots and potatoes and other vegetables 
lose quite a bit of their flavor in standing after dehydration. 
They found that if cabbage, particularly, and carrots and 
and potatoes, to some extent, after they were blanched and 
dried, were packed in an atmosphere of carbon dioxide or 
nitrogen and then sealed, they would hold their flavor much 
longer. In that case, they can use those products. The 
carbon dioxide gas is cheaper and more stable. When potatoes 
and cabbage, for example, are packed in tin cans and sealed, 
they hold their flavor and color almost indefinitely, if, 



100 
Cruess: in the case of potatoes, the dehydrated potatoes contain 

eight hundred to one thousand parts per million of sulphur 
dioxide. If they are packed in inert gas, they hold 
their flavor and color much better than if packed in air. 
That is especially true of cabbage packed in an atmosphere 
of carbon dioxide to the extent that it contains one 
thousand to two thousand parts per million of sulphur 
dioxide. 

Some products can be dried and packed without being 
held in carbon dioxide or nitrogen or other inert gas. You 
can store beets and lima beans which have been precooked 
without packing them in inert gas. That is the case with 
corn also. Onions should be packed in carbon dioxide or 
nitrogen, because they change in flavor so readily; otherwise, 
they oxidize and take on a disagreeable flavor. Peppers can 
be packed without inert gas, making them easy to pack. In 
some products the blanched product is immersed or sprayed 
with a dilute sulphite or dilute sulphur dioxide solution 
to retain vitamins and color. That is especially true of 
potatoes, cabbage, and carrots. They are sent through a 
solution of sulphur dioxide that is, the solution may be two 
or two and a half per cent of sodium bisulphite--and then 
put on trays and dehydrated. So the product after dehydration 
will contain one thousand to two thousand parts per million of 



101 

Cruess: sulphur dioxide. As I mentioned before, onions cannot be 
treated either with a high dehydration or with sulphur 
dioxide, as they adversely affect the flavor. So the onions 
are merely cut into very narrow strips and dehydrated at 
such a temperature that the pungent odor is not lost. Although, 
if you drive through the vicinity of a plant that dries 
onions, you can smell the onions for five or six miles. 
Teiser: Like the one at Vacaville? 
Cruess: Yes. 

t 

Teiser: I love the smell. 

Cruess: Yes, so do I. You would think they wouldn t have any 

flavor, but they do. They lose a lot of flavor but have 
some left when they finish drying, providing they use a 
rather moderate temperature of dehydration, not above 140 F. 
Whereas with potatoes you can use a drying temperature of 
160 F. or 165 F. without injuring the flavor and color. 

Some products have a much better flavor and color 
and keep better if they are dried quickly. Instead of using 
170 F. or 175 F., as you can before the products are dried, 
you can use quite a high temperature because the evaporation 
is so rapid when the product is unblanched. If onions, for 
example, are fresh and freshly sliced or cut into strips 
and have not dried very much or yet lost half of their water, 
the rapid evaporation keeps the temperature down. So they ll 



102 

Cruess: stand a temperature of 170 F. or 175 F. for a short time 

if they are raw. Then the temperature is dropped to the drying 
temperature of 140 F., and the flavor does not change 
markedly. 

In other words, the prepared wet vegetables, sliced 
or diced or cut into julienne strips, will stand quite a 
high temperature while they are high in moisture, because the 
evaporation then is so rapid that the product doesn t rise 
appreciably in temperature. Usually you can remove from one- 
half to two-thirds of the water before the product rises to a 
dangerous point. That method of dehydration with uncooked 
vegetables with high moisture content, dried at moderate 
temperatures, is known as parallel current dehydration. A 
parallel condition for dehydration means that you would use 
quite a high drying temperature without damaging the product, 
while it is high in moisture. 

Teiser: Was the research on this done by you and Dr. Mrak and Dr. 
Mackinney? 

Cruess: The original work was done, of course, in Germany. We simply 
applied the results of the German methods of preparing for 
dehydration. 

Teiser: Did you work on this at Davis or here in Berkeley? 

Cruess: All of our experimental work on dehydration of vegetables was 
made at Berkeley or in the commercial plants. Most of it was 



103 
Cruess: done in the commercial dehydrators. They called for 

assistance in preparing and drying the products, so most of 
our time was going from one plant of another, advising on 
preparation and dehydration methods. There were several 
plants in the south and quite a few in central California, 
that is, around Modesto, three or four; there were several 
in the Sacramento area. Most of the details of preparation 
had been worked out by the Germans. The plant at Davis was 
not built until after the war. 
Teiser: Then was your work showing the dehydrator operators how to 

apply the methods to their operations? 

Cruess: Yes, that s one thing we did. We also had to modify the 
various products and operations to meet our conditions. 
For example, very often potatoes were blanched in boiling 
water. But that doesn t give very much capacity, and the 
boiling water also dissolves some desirable water-soluble 
material. For that reason, we blanched practically all of 
our vegetables in live steam rather than in boiling water. 
So it was modifications of that sort which were made. We 
had from three to five graduate students who carried on the 
experiments for us. There was quite an increase in our staff 
at that time, and most of the increase was of either women or 
younger students who were not subject to the draft. Much of 
the experimental work was conducted by girls. 



104 

Teiser: Did they make a place for themselves permanently then in the 
food technology industries? 

Cruess: No. Most of them left at the end of the war. One boy got 
married and now lives in the South. I think he was only 
sixteen years old or younger. He worked for the University 
for several years after the war was over, so he was about 
eighteen or nineteen when he got married. He took a gal 
who was from the South and had come up to participate in 
the war work, dehydration and so on. 

Teiser: Did you work at all directly with the Quartermaster General? 

Cruess: Yes. Dr. Mrak and I carried on dehydration experiments about 
two years before America got into the war. We advised 
operators of dehydrators and told them how to get the best 
results in the dehydration of potatoes and other vegetables. 

As a result of the work on dehydration and the 
publication of it, one of the leading dehydration men in the 
War Department visited the University and [observed] the 
preparation of vegetables for drying. As a result of our 
contact with him, we became quite well acquainted with him, 
and he invited Mrak to carry on the dehydration work and 
other war work with the Quartermaster Corps. Throughout the 
last at least two years of the war, Mrak worked for the Army on 
leave of absence from the University. 

Quite important to dehydration is the tray load. 



105 
Cruess: If you pack too large a quantity of blanched potatoes or 

carrots and spread them around on trays for dehydration too 
deeply, the vegetables are apt to dry very slowly and 
unevenly. So the tray load, which is a measure of the amount 
of material of the product placed for dehydration, should be 
between one pound per square foot to one and a half pounds 
per square foot. If you put seven or eight pounds of pre 
cooked potatoes, for example, they will more or less clump 
together and dry very slowly and unevenly. So we had to 
work out the best amount of blanched material for dehydration. 
Another difficulty was in not being careful in your preparation 
of sliced or prepared potatoes and other products. The 
dehydration would be very uneven. That is, the air tends to 
go through the dehydrator unevenly, in which you have placed 
the cooked vegetables or blanched vegetables. If you are not 
careful, most of the air will go through the dehydrator below 
the product to be dehydrated or over the top. So to force 
the air to flow through the product, the tray or conveying 
device to carry the prepared vegetable for drying has to be 
arranged or so made that the air is forced through the product 
to be dried and not allowed to flow under it or over it. So 
an important feature of the dehydration of these products 
was to arrange baffles, that is, something behind or above the 
tray that forced the air to go through. 



106 
Cruess: The amount of blanching varies with the product 

somewhat. It may take as little as two to three minutes for 
a product to be blanched sufficiently to be spread on trays 
and dehydrated. Or with corn, which is blanched on the cob 
the cob and the vegetable are blanched before they cut off the 
cob, because if you cut the vegetable before it has been 
blanched, a large amount of it will shake loose and be lost. 
For corn, instead of three minutes blanching, it may take 
fifteen. The blanching period for everything except corn is 
from two to seven minutes in live steam. Peas blanch very 
quickly because, you see, they are small; individual peas heat 
very quickly, and two to at the most five minutes is 
sufficient at the boiling point. Cabbage is not blanched at all. 

An interesting method of blanching is drum blanching. 
That is, the drying is done on the surface of a drum which is 
heated inside, and the product is spread on the surface. In 
the case of potatoes, they are cooked completely, and the 
product then is spread on a drum about five or six feet in 
diameter and twenty-five to thirty feet long. That is heated 
on the inside to near the boiling point, and it dries the 
spread thin layer. Drum drying may take only two or three 
minutes. And then the product, after dehydration, dries out 
and sticks to the drum as it is rotated. On the drum are 
scrapers that scrape off the dried product. The product is 



107 

Cruess: cooked and dried very quickly. And that s used mostly for 
potatoes. It dries in a thin layer and is scraped off as 
the drum revolves and then can be packed. The usual packaging 
is in an inert atmosphere, in nitrogen or carbon dioxide. 
They have also used that method of handling for carrots, but 
it seems to work better with a white product such as 
potatoes. That has been used and is used at present, of 
course, for preparing dehydrated potatoes, but the amount of 
food that is prepared and dried in that form is less, much 
less, than what s dried on screens. 

I might say that Mrak and I published our dehydration 
experiments which were made before the war. The results were 
desired by the Quartermaster Corps, and they were published in 
a University bulletin in 1941, but published also by the War 
Department, about two years before the bulletin was published. 
Mrak was asked to transfer to the War Department shortly after 
the war had started. All of the work on dehydration was put 
together by Mackinney and me and was published as a bulletin, 
#678. It was finished in September, 1943. Most of the war was 
over but we got it published in time, so it was used to some 
extent. Another interesting thing is that of the twenty-five 
or so dehydrators that were built and operated during the war, 
only two or three have gone on. One of those that has increased 
in capacity now dries large quantities of potatoes and frozen 




Food packed experimentally for U.S. Army, World War II, about 1943. 
W.V. Cruess Emll Mrak 



108 

Cruess: shredded potatoes for commercial use. Dehydration has 

greatly increased in size. The manager of production is 
one of our graduates. 

Teiser: Who is he? 

Cruess: Ray Kuneman. The name of the plant is Simplot. The 

dehydration plants have been greatly expanded in that area; 
there are several others, mostly for frozen precooked 
products. 

Teiser: Did you work with Vacu-Dry? 

Cruess: Yes. It s an operation, of course, for the drying of onions, 
onions and garlic. We spent quite a bit of time at the Vacu- 
Dry dehydrator studying some problems that developed. 

Simplot built a dehydrator during the first part of 
World War II and dehydrated potatoes and onions. At first he 
didn t blanch, and of course they were more or less inedible. 
He spent quite a bit of time coming down to the University 
and working in our experimental plant. I spent a couple of 
weeks up there with the Simplot Company. At that time 
Kunemann was working for the government. But as soon as 
the war was over, he was asked to go to work for the Simplot 
Company, and he has been there ever since. Which reminds me 
that he sent me a sack of fresh potatoes, fifty pounds of 
fresh spuds, great big ones. 

The Simplot Company has been expanded, and they 



109 

Cruess: built several plants. One very large plant now is in the 
preparation of chemicals for the food processing industry. 
In fact, they are one of the largest users of prepared 
chemicals for the agricultural industries. This single 
company has one of the largest chemical factories in the 
United States. Simplot, of course, has become a millionaire 
several times over. He is a very nice sort of a person. I 
went pheasant hunting with him. I remember we got up at 
three o clock in the morning and drove about fifty miles 
to the place where the product is prepared for freezing. 
He has three of four large plants; they are not dehydrating 
plants. They include factories for producing fertilizer such 
as sulphate, phosphate, and potassium chloride. He makes a 
tremendous amount of processed frozen pack potatoes, corn, 
thousands of pounds of wool, dressed beef, lambs for killing 
and dressing, much lumber, many tons of chemical fertilizer and 
so forth. 



110 



ADDITIONAL DEHYDRATION DEVELOPMENTS 

Cruess: The rate of drying, as you might guess, depends 
on the temperature and the rate of air flow. If air is 
carried through the prepared vegetable at the speed of 250 
feet per minute, the product takes 5.2 hours to dry. If 
the rate of flow is increased from 250 to 500 feet per minute, 
dehydration is complete in four hours instead of 5.2. If 
it is increased to 700 feet per minute, the drying time 
drops to 3.5 hours. About the highest rate they use is 
about 1,000 feet per minute. In fact, 700 feet per minute 
velocity is the usual speed. But at 1,000 feet per minute, 
it takes only 3 hours. Increasing the air flow from 250 
to 1,000 more than doubled the rate of drying. We found 
that slow drying was sometimes due to insufficient rate of 
air flow, which meant they had to build larger equipment for 
conducting air through the prepared vegetables. 

An interesting thing we developed at the University 
I guess twenty-five years ago. If you go camping at a high 
altitude and try to cook dried vegetablesdried potatoes or 
dried carrots--f irst soak the product until it is plump. 
Then cook it over the campfire. But we found that ordinary 
red beans, precooked sufficiently to be eaten, and then 
dehydrated--cooks very fast the product can be used in the 



Ill 

Cruess: camp. You can use the ordinary white beans, but the flavor is 
better if you use red beans. They are cooked until they are 
ready for the table. Then they are spread in a dehydrator 

and dried at quite a high temperature. The product stands 

o o 

a temperature of 175 F. or so instead of 120 F. Although 

the cooked beans pop open more or less during dehydration, 
they soak up water very quickly and cook in a short time. 
So you can save a lot of time by preparing precooked red beans 
that are preflavored with sliced onion and garlic if you 
want. My wife doesn t like garlic, so I leave it out. 
The product cooks rather quickly in water and flavoring 
material. So far this is not used commercially; it is used 
by people who like to go to the mountains, and whom we have 
known for quite a while. 

One difficulty with all of these products, I think, 
whole beans and other products especially, that plump up 
during preparation for dehydration, during cooking they 
expand. Carrots are thoroughly washed in a revolving drum and 
with a special series of knives cut into thin sections. 
The sections go through a cutter that cuts them into julienne 
strips. Then they are spread on trays and dried. Although 
the flavor is much better retained if the carrots are 
blanched thoroughly before they are placed in the dehydrator. 
So if the product is to be cooked quickly, it is blanched 
sufficiently to cook the product all the way through, and 



112 

Cruess: that may take ten minutes. But most of the carrots are cut 
into julienne strips and blanched ten minutes or so in live 
steam, until the carrots are practically cooked. They are 
not cooked sufficiently to be put on the table, but they are 
blanched enough that when they are dried they don t taste 
off in flavor and are not tough. That means that carrots 
are blanched from seven to ten minutes in live steam. They 
are usually dehydrated by parallel current dehydration and 
finished at a lower temperature. The dehydration is begun 
at about 185 F., and the drying is so rapid that the product 
doesn t reach a temperature that damages the flavor. Then 
the drying is continued and completed at a somewhat lower 
temperature. The finishing temperature is usually around 
150 F. The dehydration takes about ten hours. 

The onion, on the other hand, of which there is 
quite a large quantity prepared, is prepared for drying by 
removing the roots and the skin, the paper outer skin. 
That can be done cutting the onion into slices. After 
slicing, the adhering shell of skin is removed very readily 
by passing the dried vegetables through a drum. That is, 
the dried onion is broken up into small peices, and the skin 
is very readily separated by revolving the drums. If the 
onions are finished and dried at a temperature of 120 F. to 
150 F., they retain enough flavor to be desirable. If you 



113 
Cruess: use high temperatures to increase the rate of drying, you 

may lose so much of the flavor that the product, when cooked, 
doesn t taste like onions anymore. 

Potatoes are another product that is dried and 
packed in large quantities. The mashed potatoes may be 
dried over a drum and then ground and sifted and packed for 
quick-cooking mashed potatoes. Quite a lot of potatoes in 
that form are used. The cubes or strips are precooked too. 
When potatoes are prepared for dehydration, they are of 
course lye-peeled in a ten to fifteen per cent sodium hydroxide 
solution, and thoroughly washed in a drum in water, and then 
they are carefully trimmed and the undesirable pieces are 
entirely removed. The peeled potatoes are carefully sorted 
to remove all the material that is not fit for drying, so 
the loss in peeling and trimming is very large. Maybe a 
quarter to a third of the potato is lost in peeling and 
sorting. It is cut into cubes, or it can be cooked and 
dried in a drum to make mashed potatoes, or it can be cut 
into shoestring strips and so on. Commercially, most of the 
prepared and blanched, diced or shoestring potatoes are put on 
screen trays about three feet wide and six feet long or 
three feet by three feet and then put into the drying 
compartment, where they are dried at a temperature of at 
most about 160 F. If the dehydrator is six feet to eighteen 



114 

Cruess: feet long, at this end it will heat the product to the drying 
temperature that is used for julienne strip potatoes, will 
be as low as 110 F. where it goes into the dehydrator and 
will gradually increase in temperature as it travels through. 
The finishing temperature, where the product is dried for 
the last two or three hours, may be 160 F. or 165 F. 

For the Army, the dried potatoes are packed with an 
inert gas to prevent changes in flavor during storage or 
shipping. But for household use, they are packed in one or 
two pound cartons, because the housewife doesn t want to be 
bothered with a large quantity of material. She couldn t 
use one hundred pounds of dried potatoes. One of the problems 
with potatoes is the clumping together during drying, and for 
that reason the tray should not be overloaded. The load for 
blanched precooked potatoes is one to one and a quarter 
pounds to one and a half of thoroughly blanched spuds. They 
are blanched for six to seven minutes. They enter the dryer 
at about 120 F. and gradually progress to the finishing 
temperature of 160 F. It usually takes six to seven hours 
to dry the shoestring potatoes. For the Army, they treated the 
prepared shoestring or julienne strip potatoes with bisulphide 
solution. The prepared vegetables passed through a tank of 
bisulphide solution, but the treatment with sulphur dioxide 
is unnecessary for the product for household use and wouldn t 
be desirable, because much of the flavor may taste of 



115 
Cruess: sulphur dioxide when the product is treated with a solution 

of bisulphide. It was necessary for the product for Army use, 
because it might be a year or two year before the boys got 
around to cooking the product for use, or be stored and 
the warehouse might not be open for a year or so. 




William V. Cruess 1965 



116 



DR. MRAK, DR. JOSLYN,AND DAVIS 

Teiser: Was Dr. Mrak a student of yours? Was that how you first 

came to know him? 
Cruess: Yes. As I ve often said, we raised him from a pup. We 

got him when he was a student in food technology and had 

him in our courses from the time he was a freshman until he 

was a graduate student. 
Teiser: Could you tell when he was a freshman that he was going to 

be an outstanding food technologist? 

Cruess: Only by his grades. He had a very high grade point average. 

/ 
Another one who was even better was Dr. Joslyn. Joslyn 

and Mrak were both "A" students. Joslyn was in the College 
of Chemistry, and Mrak was in what is now called nutritional 
sciences, in the College of Agriculture and Experiment 
Station. At that time there was no department of nutritional 
sciences, and we were in the College of Agriculture. The 
title of our work was food technology. Way back about twenty 
years ago, soon after World War II, all of the work on food 
technology was transferred to Davis. Dr. Mrak became the 
director of food technology at Davis, and some of the other 
men also went to Davis. I retired at about that time, so 
I didn t go to Davis permanently. I was there during the 



117 

Cruess: three or four years of preparation for moving the department 
to Davis. Dr. Joslyn decided he didn t want to live in 
Davis, so he was transferred to the department of nutritional 
sciences, Mackinney also. Those two were not transferred 
to Davis. I think the dean should have been hard-boiled 
and have transferred all of us. I begged off because I was 
retiring at about that time, and instead of going to the 
expense of moving from Berkeley to Davis and building 
a new place to live, I stayed in Berkeley. However I bought 
a place at Davis and still have it. It has not brought a 
very large return; it is not a very fancy place, but it is 
good enough for the location. I planned to expand it quite 
a bit and put in better storage for dehydrated and canned 
products. 

Teiser: Is this a farm? 

Cruess: It s right in town but quite convenient to the University, so 
I could easily have walked back and forth. 



118 



PARTIAL INDEX 



119 



Agricultural Engineering, Department of, University of 

California, Davis, 91 
Agriculture, Department of, 9 

see also College of Agriculture 
Almaden Vineyards, 34, 35 
Alsberg, C. L. , 57 
Anderson Barngrover Company, 83 
Ash, Charlie, 18 

Ball, Richard, 41 

Bedford, Cliff, 82 

Bell Olive Company, 41 

Bettoli, Rudolph W. , 12, 21-22 

Biddle, Henry Chalmers, 3 

Bioletti, Frederick!., 9-10, 12, 17, 20, 66, 83, 85 

Birdseye, Clarence, 75 

Blasdale, Walter C. , 3 

California Olive Association, 40, 45-46 
California Wine Association, 18-19, 23, 36 
Canners League of California, 47, 48 
Canning, 44, 46-48, 60-61, 70 
Chemistry, College of, University of California, 

Berkeley, 2-3, 4-5 

Christie, Arthur W. , 29-30, 49, 82-86, 87, 90, 92 
Colby, George, 8-9 
College of Agriculture, University of California, 

Berkeley, 5, 7, 9, 16, 17 
Colton Winery, Martinez, 12-13, 21 
Commercial Fruit and Vegetable Products by 

W. V. Cruess, 44-45 
Concannon, Joseph, 25 
Concannon winery, Livermore, 25 
Cresta Blanca Wine Company, 26, 35, 36 
Cruess, William V. , Sr., 2 

Dehay Winery, Cloverdale, 15-17 

Dehydration, 29-30, 44, 49, 80-115 

Dried Fruit Association of California, 49 

Early California Foods Company, 37-38 
East Side Dryer, 83 
Eidt, C. C. , 88 



120 



Flossfeder, Friedrich C., 85 

Food technology (academic study of), 28-30 

Frozen foods, 68-79 

Click Olive Company, 37-38 

Haraszthy, A. , 52 

Hawaiian fruits, 76-77 

Hilgard, Eugene W., 9, 13, 20 

Holm, Hans, 10 

Hunt Brothers Cannery, 66 

Institute of Food Technologists, 47, 48-49 
Italian Swiss Colony, 21-23, 34 
Italian Vineyard Company, Guasti, 23 

Jaffa, Myer E., 7-8, 11 

Joslyn, Maynard A., 50, 53, 70, 72, 73-74, 76, 116-117 

Kuneman, Ray, 108 

Lachman, Arthur, 52 

La Junta Club, 5-6 

Leonard, John, 83 

Lewis, C. I., 28 

Lindsay Ripe Olive Company, 37-38, 43 

Louis M. Martini winery, 34-35, 55, 56 

see also Martini, Louis M. and Martini, Louis P. 

Mackinney, Gordon, 102, 107, 117 
Marsh, George L. , 72, 73-74 
Martini, Louis M. , 52, 54, 56 

see also Louis M. Martini winery 
Martini, Louis P. (Louis, Jr.). 54-55, 56 
Meyer, K. F., 62 
Morgan, Agnes Fay, 8 
Morgan, William Conger, 3 
Mrak, Emil, 50, 53, 102, 104, 107, 116-117 
Muir, John, 14 

National Canners Association, 46-48 

Nichols, Paul F., 87, 90, 92 

Nutrition department, University of California, 8 



121 



Olives, 37-43, 45-46, 57-67, 77-78 

O Neill, Edmond, 2-3 

Orange juice, frozen, 70-73 

Oregon State College of Agriculture, 28 

Overholser, Earle L., 68-69 

Pacific Olive Company, 41-42 
Pacottet, P., 20 
Pear Growers Association, 15 
Prohibition, 15, 22-28, 49 
Prunes, 80-82, 83-84, 90, 91, 93 
Pucinelli, Ed, 92-93 

Quartermaster Corps, 104, 107 
Reed, Harold, 87 
Saywell, Lawrence G. , 53 

Sheehan, E. M. , 52 

Sherry experiments, 31-36, 54 

Simplot Company, 108-109 

Smith Olive Company, 37-38 

Smith Winery, 16 

Swett, Frank, 13, 15, 52 

Swett, John, 13-15 

Swett Winery, 13, 14-15 

Tressler, D. K. , 75, 79 
University Extension, 53 

Vacu-Dry Company, 108 

Vaughn, Reese H. , 64 

Viticulture, Department of, University of California, 9 

Walnut Growers Association, 30, 49, 82, 86, 87 
War-related dehydration research, 89, 93, 94-96, 99, 

102-104, 107, 108, 114-115 
Wente Brothers winery, 26-27 
Wetmore, Charles A., 26, 52 
Wetmore, Clarence J., 26 
Wheeler, Benjamin Ide, 3-4 



122 



Wiegand, E. H. , 29 
Wine, 9-10, 12-36, 50-56 

Zymology, 10, 11 



BERKELEY: DEPARTMENT OF NUTRITIONAL SCIENCES 

3 / 5 ti:t?~J 

April 10, 1967 



Mrs. Wi I la Baum 

The Bancroft Library 

Regional Oral History Office 

Room 486 

University of California 

Berkeley Campus 

Dear Mrs. Baum: 

I am enclosing herewith five copies of the written agreement 
covering use of the manuscript. I note that your letter of 

April 3, 1967, states that any quotation for publication requires 
the written permission of the Director of the Bancroft Library, 
and that he will notify me before so permitting. That will be 
perfectly satisfactory to me. 

It will be satisfactory to me for you to make a copy available 
to the Department of Special Collections Library, Davis Campus. 
I do not know any other special depositors that should receive a 
copy, but if you know of any I would be glad for you to authorize 
any such request. 

I am leaving Monday morning from San Francisco air port for 
Hawaii for two weeks "vacation" with Mrs. Cruess. As you know, 
I am not in the best of condition physically and if on that account 
anything should occur to delay or prevent completion of the 
manuscript, etc., etc., you, Miss Teiser, and our office have my 
permission to take care of any arrangements, etc., including 
authorization to transfer to the Bancroft Library reprints, books, 
etc. that I have planned to place with the Bancroft Library. Our 
secretary knows where they are located in my office. She, Dr. M. A. 
Joslyn, and Dr. G. Mackinney of our department know where all such 
are located and have my full permission to transfer or make any 
disposition of them that seems desirable in the circumstances. 
I do not, of course, expect any such "calamity" but I mention this 
"just in case". 

Yours sincerely, 
]/*" ^ ^ i 

"**Z^F ~" 

( <*- 

W. V. Cruess 

Professor of Food Science 

and Technology, Emeritus 

WVC:cb 
Enc losures 



BERKELEY: DEPARTMENT OF NUTRITIONAL SCIENCES 



May 4, 1967 



Mrs. Wi II a Baum 

The Bancroft Library 

Regional Oral History Office 

Room 486 

University of California 

Berkeley Campus 

Dear Mrs. Baum: 

Since your letter of April 31, I have read the manuscript 
a second time and made a few additional notes and suggestions. 
I am transmitting a copy herewith. 

I still have to prepare a short statement on the recent happenings 
in food technology at Davis. The two weeks of vacation in Hawaii 
was a good antidote for the preceding work on the manuscript. 

Thanks again to you and Miss Teiser for carefully reading 
and correcting the manuscript. It was a colossal task. 

Yours sincerely, 



W. V. Cruess 

Professor of Food Science 

and Technology, Emeritus 

WVCrcb 
Enc losure 



BERKELEY: DEPARTMENT OF NUTRITIONAL SCIENCES 



May 18, 1967 



Mrs. Villa K. Baum 

Bancroft Library 

Room U-86 L 

Regional Oral History Office 

Berkeley campus 

Dear Mrs . Baum : 

This will acknowledge your letter of May J, 19o7> stating 
that it will be at least six months before completion of 
typing of the bound copy of the W. V. Cruess writings. 

I deeply appreciate all that you and Miss Teiser have 
done in transcribing my notes and the tremendous task of trans 
cribing, correcting and typing of these notes. Because of my 
illness and very imperfect dictation and correcting, your work 
has been unduly difficult. You have been completing the task 
in a very satisfactory (and more than satisfactory) manner. 
Many, many thanks. 



Sincerely, 




W. V. Cruess 

Professor of Food Science 

and Technology, Emeritus 



WVC/cz 

cc: Miss Ruth Teiser 



BERKELEY: DEPARTMENT OF NUTRITIONAL SCIENCES 



May 10, 1967 



Mrs. Wi I I a Baum 

Regional Oral History Office 

486 Library 

University of California 

Berkeley Campus 

Dear Mrs. Baum: 

The accompanying statement gives the information that you 
requested concerning the Food Technology building at Davis, 
California. I shall be glad to furnish any additional information 
that you may need on this subject. 

We have sent to you several bound copies of various reprints 
and a set of unbound reprints that you may wish to include with 
the other material for the Bancroft Library file. 

Yours sincerely, 




W. 

Professor of Food Science 
and Technology, Emeritus 



WVC:cb 
Enc losure 



The Department of Food Science and Technology at Davis* 

For many years it was increasingly evident that research and 
instruction of food technology in the College of Agriculture should 
be centered on the Davis campus for the following reasons: The 
production departments, such as Pomology, Truck Crops, Viticulture and 
Enology, Agronomy, Animal Science, Dairy Science (now part of Food 
Science and Technology), and possibly others were located at Davis. 
Fruits, truck crops, animal products and dairy products are produced 
and available at Davis. Also fruit and vegetable growers and producers 
of live stock and dairy products are conveniently located near Davis. 

For a considerable number of years Dean Hutchison favored moving 
the department to Davis and sought from the Legislature and the University 
administration funds for that purpose. In 1939 the Legislature appropriated 
$750,000 to construct a building for Food Science and Technology on the 
Davis campus. The war delayed construction. In 1948-49 an additional 
$500,000 was requested. The University administration issued authorization 
to undertake the drawing of plans for the new building. Goodpaster 
of Sacramento was authorized to draw up the plans. 

The principal contract for construction of the building was signed 
in 1949, and actual construction was begun in 1950. Michael Heller (now 



The writer is indebted to Dr. B. S. Luh for much of the information 

on the Food Science and Technology Department in the College of Agriculture 

at Davis, Ca I i forn ia. 



, 

I 

. . . 

. 
, 

. 
, 
. 


, 

: 
. 

, 
. 

i 





. 

, 






-2- 

the Continental Hel lor Corp.) of Sacramento was the principal contractor. 
The plans were drawn by the University architects who also supervised 
construction. A committee of the Food Technology Department conferred 
frequently with the architects before and during construction. Construction 
was begun in 1950. As I recall it, the building was completed and 
accepted by the University in 1952; and occupied in 1953. It was 
named Food Science and Technology; later in I960 it was officially named 
"Cruess Hall" during a luncheon meeting on the Davis campus on March 19, 
I960. 

Several years before transfer of the department to Davis, Dr. E. M. 
Mrak had become head of the department. In 1959 he became Chancellor 
of the College of Agriculture at Davis. Dr. George Stewart became head 
of the Food Science and Technology Department until 1963. Dr. R. H. 
Vaughn was in charge of the department until 1966. Dr. Vaughn recently, 
1966, gave up chairmanship of the department and Dr. C. 0. Chichester 
is now the department head. 

The building has 65 rooms as follows: 

Number of Rooms 

a. Laboratories 18 

b. Offices 14 

c. Constant Temperature Rooms 4 

d. Freezing and Cold Storage Rooms 

e. Pi lot Plant 

f. Experimental brewery 

g. Service Rooms: 

Autoclave Room 

Balance Room 

Calculator Room 

Gas Chromatography Room 

I nstrument Room 

Kjeldahl Nitrogen Room 

Machine Shop 

Paper Chromatography Room 

Photography Room 

Sensory Evaluation (flavor) rooms 

Storage Room I 



. 
. 
. 

. 
. 

i 





i 









. 



-3- 



Supply Rooms 2 

h. Special Conference Room I 

Tota I 65 

Number of staff members in Food Science and Technology, exclusive 

of those in Dairy Science Building, 21. 

Total number of staff members including those in Dairy Science 

Building, 32. There is no longer a Dairy Science Department; it has 

been combined with Food Science and Technology, with Dr. C. 0. Chichester 

as head of the combined department. 



, 

. 

. 

. 

. 




Cruess Hall before addition 




Professor of Food Science 
and Technology, Emeritus 



D 

U 

E 

S 
S 



March 19, 




University of California 

Davis, California | 




* 




DR. Wm. V. CRUESS 






Ruth Teiser 

Born in Portland, Oregon; came to the Bay Area 

in 1932 and has lived here ever since. 

Stanford, B. A., M. A. in English; further graduate 

work in Western history. 

Newspaper and magazine writer in San Francisco since 

1943, writing on local history and business and 

social life of the Bay Area. , 

Book reviewer for the San Francisco Chronicle 

since 1943. 



7