Skip to main content

Full text of "Plant control of the engineering operations at the Calvert Distilleries, Relay, Maryland."

See other formats



I. Summary 
II. introduction 
III. Raw Material Tests 
A. Grain 
a . Yeast 
U wa^er 
D. jmeis 
IV. Main Process 

V- By-Products 
v I . Aging 
VII. .Blending 
VIII. Conclusion — Engineering Control 
IX. Bioliograpny 

ii// 7/ 39 


The completely modern distillery oi tiie Calvert Com- 
pany at Relay, Maryland was designed to facilitate operation by 
the use or central control stations. Liberal use oi automatic 
recorders and regulators mecnanizes process control to a nigniy 
ef I'ic ient degree . 

The production or alcohol oy bacteriological processes 
requires a caret ul and systematic regulation which can only be 
maintained oy complete chemical Kn ovrledge or conditions or reac- 
tion determined irom tests and analysis. For this reason, the 
Calvert plant employs a stan or trained technicians to .Keep con- 
stant cneca on the chemical prboes3es oi the production. 

TYie transformation oi grain into alcohol involves the 
conversion or the grain starch to sugar and rermentation or the 
sugar into alcohol and caroon dioxide oy tne action or yeast. 
These reactions require careful regulation of xemperatures and 
pressures to give maximum yields. 

All raw materials, as they arrive at the plant, must "be 
tested for quality and to meet certain standards before their 
use in production is permitted. 

In the main proce33, samples withdrawn for test at 
every point where it is advantageous to know the condition of 
the product. The preparation of fusel oil and cattle feed re- 
quire observation as well. 

The process of aging and blending the liquors is carried 
out under the supervision of the plant chemists. Careful tests 


for quality control aid in the production of a uniform product. 

The up-to-date equipment used and careful maintenance 
of control make the Calvert Distilleries one of the most modern 
plants in the world. 


Careful and sj^stematic control of the plant operations 
at the Calvert Distilleries of Relay, Maryland has "been estab- 
lished to insure the production of a whiskey of uniform quality. 
The completely modern plant, situated on the Washing ton -Baltimore 
Boulevard in the valley of the Patapaco "River, has adequate and 
up-to-date facilities for careful testing and control of the en- 
tire process from examination of the raw materials as they are re- 
ceived at the plant to the testing of the final product as it 
leaves the blending department. The plant makes liberal use of 
automatic recorders and regulators for complete control of all 
operations involved in the production of spirits of grain and the 
by-products, fusel oil and feed for live stock. 

Obviously production of any material for human consumption 
requires close supervision of the purity of starting materials and 
careful control throughout the entire process to prevent possible 
contamination. In addition to the control of quality, a know- 
ledge of the' condition of the product at each stage of production 
is vital before proceeding to the next step. Adjustment of the 
operating conditions to those that have been found by experience 
to be superior is necessary if the nlant is to operate at maximum 
efficiency and at the same time produce a quality product. With 
this thought in mind, the Calvert plant was designed to mechanize 
control of the engineering operations by bringing together the 
means of adjustment and the instrument readings on central control 



boards for each individual unit. This enables the operator to 
have "before him all the necessary data showing the conditions 
of the process, and, by remote control, a way to make correc- 
tions. The operations involved in the production of distilled 
spirits are of the nature that require constant coordination of 
temperatures and pressures for optimum conditions of production. 

Briefly, the production of alcohol by fermentation is 
a bacteriological process in which the natural starch occurring 
in varied types of grain is converted to sugar by the action of 
diastase present in malt. The sugar formed is then allowed to 
ferment from the action of yeast and the decomposition products, 
ethyl alcohol and carbon dioxide, are produced. 



Starting their tests with the grain as it arrives at the 
plant, the Calvert chemists sample each carload to be sure that 
it is up to standard in every detail. These tests involve mea- 
surement of apparent grain density, moisture content, per cent 
dockage, bacteria count, per cent starch, etc. The density is 
measured by means of a standard Government balance that is cali- 
brated to read directly in bushel weight from the weight of the 
fraction used. By passing a typical sample of the grain through 
revolving electrodes, between which there is a standard impressed 
voltage, it is possible to obtain an accurate indication of the 


moi3ture present from the amount of current flowing. The grain 
is then passed through a sifter to separate it into particle 
sizes and to measure ths amount of fine material present that 
must "be discarded. This facilitates the examination for damaged 

The bacteria count must be taken for every carload of 
grain to be sure the grain meets the standard specifications of 
the industry. 

In order to be able to calculate plant efficiency, the 
starch content is determined quantitatively on an average sample 
of the rye, corn ;tnd malt used. This determination is made weekly. 

Various other tests of a specialized nature are applied 
to the grains as they are received. For example, malt is extrac- 
ted to measure the per cent sugars in water solution and, when 
needed, the quantity of diastase present is run. 

The grains used must necessarily meet certain require- 
ments or they are rejected because use of a poorer grade of raw 
material results in an inferior product of low yield. 


While the yeast may seem to be of secondary importance 
to the main raw material used, its preparation is one of the 
mors difficult operations, requiring delicate control. Since 
it is the enzymes in the yeast that are responsible for the 
fermentation of sugars into the desired alcohol, it is of ut- 
most importance that the yeast culture be free from contamina- 


tion. The yeast is first prepared in the Bacteriological Labra- 
tory from pure cultured stock. Aftsr sufficient time, it is 
transferred to larger containers and allowed to ferment and grow, 
using malt extract as a culture medium. The final growth is car- 
ried out in 3,000 gallon tinned copper-bearing 3teel vessels be- 
fore being planted on the bulk of the mash. A culture of lactic 
acid -producing bacteria is used to inoculate the fermenting mash 
in order to produce what is known as "lactic sour" to protect the 
yeast from action of common bacteria. 

C . WATER ■ 

A discussion of raw material control would be incomplete 
for the distillation industry without mention of the water used, 
for the reactions involved require large amounts. At the Cal- 
vert plant, water from five deep wells is pumped to supply a 
one and one-half million gallon resevoir, which can be spring 
fed if needed. The water i? treated with coagulating alum and 
the floe formed is allowed 10 settle. From the settling basin, 
the water passes to the filters, for further purification. Chlor- 
ination is the final process. 

The boiler feed water is tested for hardness and treated in 
an 8,000 gallon per hour "hot lirae-sada" softener for the pro- 
tection of the boiler. Sodium sulfite is here added to combat 
oxygen that might be present in the water. 

The water to be used in the blendin? process is distilled 


in a 1300 gallon per day steam-heated still. Analysis of this 
water is made for the presence of copper, iron and residue. 
Since it is to be used for dilution of the final product to the 
desired proof, it 13 necessary to know the pH value as well. 

D . IWL8 ■ 

The Calvert Distilleries operate their own power plant 
so their organization of chemists checks the fuels used for 
power as a further means of extending control. Moisture, fixed 
carbon, fusion point, B.T.U. content, volatile material, and ash 
are all determined. 


On the accompanying flow sheets the points in the process 
where samples are withdrawn for test are marked in red to give an 
idea of the completeness of the supervision given production in 
a modern plant. The tests conducted are designed to indicate 
the condition of the entire batch of material. 

Grain from the railroad siding is unloaded by means of 
a ^screw conveyor, capable of handling 1000 bushels per hour, 
and carried to the top of an elevator, where it is cleaned and 
screened to discard about two per cent. As needed, the grains 
are allowed to descend over magnetic separators to remove metal 
particles and passed to the high speed mills for grinding. 



The meals thus prepared are sent to bins for future use. 
It is at this point that starch content is determined. As needed, 
the meal is conveyed to the top of the main process building, 
where it is weighed continuously t,o the oroper proportions by con- 
trol from a central panel on the third floor. This is approxi- 
mately 85 per cent rye and 15 per cent malt, which is mixed with, 
warm water on its way to the cookers. The mash is brought quickly 
up to 150° P. by the entrance of live steam and held for an hour 
at which time it is lowered into drop tubs to continue conversion 
of the starch to sugar. Here in the process the pH value (about 
5.5 is right for best conversion), acidity, and the ratio of mal- 
tose to dextrine are determined. 

The mash, as it leaves the drop tub3, is again sampled 
and nested on its way to the coolers where the temperature is 
lowered to about 80° F. From the coolers, the mash is piped to 
one of the fifteen large fermenters to be inoculated with yeast. 

This fermentation process occurs in 40,000 gallon tanks 
equipped with air pipes, cooling coils and live steam outlets 
for sterilization. 

Tests are run daily to determine the degree of fermenta- 
tion on what is known as 24, 48 and 72 hour beer. These include 
specific gravity, acidity, and pH. 

'So attempt is made to recover the C0 o formed in the fer- 
mentation, for it is believed that the reaction is more complete 
when open to the atmosphere. 

The mash is pumped from the ferment er 3 "co the "beer wells" 
in preparation for distillation. 

1 ^^^—M 

^^^^a_-2l T~— — — 

i^iiTit ip-~ 

- 1 i 



^^^^^ "^9^ 







The equipment for the distillation of the prepared mash 
is a five column unit consisting of "beer, aldehyde, rectifying, 
pasfurizing and fusel oil columns for the separation and purifi- 
cation of the ethyl alcohol farmed from the other products of 
f ermsntation. The residue, or spent beer, is tested for the per 
cent alcohol present as it leaves the beer column. 


Ho distillery for the production of grain spirits would 
be complete without a plant for the recovery of the grain tissue 
remaining for use as cattle food. At the Calvert plant, the 
spent grain travels to a separate building where it is screened 
and pressed to separate a large amount of cake from the beer. 
The remaining liquid is then evaporated to a thick syrup and 
mixed with dried meal to pass into a revolving steam-heated dryer. 
Testing is necessary of the final product to be sure that certain 
requirements are met. Bushel weight, moisture, protein, fat and 
fibre are among the items controlled. 

The fusel oil that is recovered from the distillation 
consists of a mixture of higher alcohols and is 3old to chemical 
companies for their recovery. 


As it comes from the still 3, the alcohol is approximate- 
ly 110 proof and water white- It must now be aged in charred 



white oak barrels for at least four years, during which time it 
absorbs certain tannates from the wood to acquire a color and 
flavor, and at the same time loses some of its undesirable pro- 
perties. For thi3 reason, the barrels must be of a high grade, 
tested and examined wood, or the process of aging will be a fail- 
ure. The barrels are filled, under Government supervision, and 
stored in bonded rack houses. The Galvert warehouses have a to- 
tal capacity of 308,000 barrels, kept at constant temperature 
and humidity throughout the four years of aging. 


Liquors of the same type from many barrels are tapped 
and mixed in large vats to be used in blending a uniform product. 
Tests are made to know the exact nature of the constituent types 
in order to control the final blend. The bottles to receive the 
whiskey are titrated for alkalinity because an excessive alka- 
line condition will darken tannins present and cause precipita- 
tion of small amounts of metals. 

xo complete the path from grain to alcohol under careful 
ohemical observation, the final product is checked by Calvert 
chemists for color, hydrometer proof, boiling point, pH value 
and per cent fill of bottles. 


Operation of the pro cesses of production at the Calvert 
Distilleries exemplifies modern industry where maintenance of a 



highly skilled staff of technicians for the control of the con- 
ditions of production is essential. It is highly advantageous 
to produce under such conditions of control both economically 
and from consideration of the purity of product. 

The unit processes are greatly simplified in their opera- 
tion from an engineering point of view "by having central stations 
to control entire units. Such laas been the experience of modern 
engineering practice at the Calvert Distilleries. 

The materials to "be used in production are mechanically 
conveyed to the points in the process where they are needed and 
the amounts used are automatically weighed and recorded. An am- 
ple supply of temperature -measuring devices, pressure recorders 
and flow meters are used to know the exact quantities of materials 
used and the conditions of their reaction. The plant has there- 
fore a simplified control of operation, combined with a complete 
chemical check to make it one of the most modern distilleries 
of the world. 



"With the Institute at the World' 3 Largest 
Rye Distillery" -- Chemi cal and Met al- 
lur gi ca l Engin soring ( Nov emb e r , 1936 

CalTert Distilling Company Pamphlet, "Produc- 
tion of Whiskey and Grain Spirits." 

Mr. Hurley, Chief Chemist, Calyert Distilling 

Mr. Gallop, Educational Department, Calvert 
Distilling Company. 


Masir Co'/i"f C»//s 

Groin trtrf 




Sy r "A