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

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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

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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

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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