Introduction

This report gives the results of the first season's work on the cold storage of apple cider. It is hoped that these 
investigations may later become the basis of definite recommendations for commercial practice. The plan of the 
work has been to prepare cider in the laboratory, cool quickly to C. (32 F.), then store at C., and examine from time 
to time during storage.

Mr. W. A. Taylor, pomologist in charge of field investigations, Bureau of Plant Industry, has cooperated in 
suggesting the varieties of apples used and in selecting the localities from which the fruit was obtained, with a view 
to giving the results a wide application. Mr. Taylor, Mr. George C. Husmann, and Mr. W. N. Irwin, of the Bureau of 
Plant Industry, have also furnished valuable organoleptic notes on the ciders at intervals during storage.

THE FRUIT USED FOR THE EXPERIMENT.
The fruit purchased was of the grade commercially known as "seconds." Upon delivery at Washington it was stored
in a warehouse in a room kept at 32 F., as it was not practicable to begin the experiments when the apples were 
received. Considerable decay occurred during cold storage in the case of the first five varieties of apples 
mentioned in Table I. This was to be expected, because the apples were not of the first grade; but very little decay 
was found among the last four varieties mentioned.

The following facts should be noted in connection with the composition of the juices as given in the table. The 
content of sugars is probably higher than if the apples had been ground as soon as received. This is particularly 
true of the three late winter varieties, Baldwin, Golden Russet, and Roxbury Russet, on account of the well-known 
fact that most fall and winter apples contain starch at picking time, which disappears rather rapidly in common 
storage, and slowly in cold storage. On the other hand, the acid content is probably much lower than if the apples 
had been ground at once, because acid is lost rapidly during cold storage. These facts have been repeatedly 
demonstrated. The composition of the first six juices is fairly typical of average American varieties.6 The last three
juices were exceptional products and show what may be produced should the demand arise. They were very rich in 
sugars and in acid, and in every way were of very high quality. The high sucrose content of the Roxbury Russet is 
noteworthy.

Preparation of the Cider.
The quantity of apples made into cider amounted to 2 barrels of each of seven varieties, to 6 barrels in the case
of the Baldwin apples, and to 1 barrel of the Kentucky Red. All rot was removed from each lot of apples before
grinding. The method of preparing the juice closely approximated standard commercial practice. The fruit was
ground in a rotary apple grater of the type usually employed in grinding apples, and was pressed in a powerful
hand power press. Racks and cloths were used, following in this respect the usual American method. The racks 
were 36 inches square, and each cheese was 32 inches square and about 3 inches thick. One cheese held the 
grated pulp from a barrel of apples. For the cold storage experiments, 5-gallon kegs were used as containers for 
the juice from eight varieties, and a fifty gallon barrel was used for the Baldwin Cider. These containers were well 
steamed, and rinsed with clear, cold water immediately before use.

After filling the kegs they were placed either out of doors or in a freezing room at the cold-storage warehouse, thus 
cooling the cider rapidly. The data in regard to the cooling are as follows:

Temperature changes of the ciders from the time of pressing until placed in storage at 32 F.

	Tolman: Temperature when pressed, 15 C. Stored out doors over night; temperature
	then 3 C. Then sent to cold storage.
	Winesap: Temperature when pressed, 15 C. Stored outdoors over night; temperature
	then 12.5 C. Sent to freezing room, storage warehouse (temperature 11 F)
	for nineteen hours. The juice had cooled to 1.5 C with slight formation of ice;
	removed to storage at C.
	Yellow Newtown: Temperature when pressed, 14.5 C. Sent at once to freezing room.
	In nineteen hours had cooled to 1.5 C, with some formation of ice. Sent to
	storage at C.
	Rails: Temperature when pressed, 16.5 C. Kept out doors over night; temperature
	15.7 C. Then sent to freezing room; six hours later the juice was found to have
	cooled to 6.5 C. It was then removed to storage at C.
	Gilpin: Temperature when pressed, 18. 5 C. Held out doors over night; temperature
	then 15.8 C. Sent to freezing room; six hours later juice had cooled to 6.5 C.
	Then removed to storage at C.
	Baldwin: Temperature when pressed, 13.5 C. Held out doors over night; in the
	morning, temperature was 12.5 C. Juice then sent to freezing room and left for
	three days. During this time the temperature of the juice fell to 2 C, and
	much ice formed in the barrel. Juice was now removed to storage at C.
	Golden Russet, Roxbury Russet, Kentucky Red: These three varieties were pressed on
	the same day. Temperature when pressed, 14.5, 14.0 and 14.5 respectively.
	Sent to freezing room and removed after twenty-four hours. Temperature, 2 C.
	Some ice formation had occurred. The three lots of juices were sent to storage
	at 0 C.

After the casks had been placed in their final positions in the room at the warehouse, a f-inch hole was bored in the 
head of each, to serve as a vent in case of gas formation, and through which samples could be withdrawn. Except 
when samples were being taken the holes were kept plugged with cotton.

The ciders were sampled frequently during the first weeks of storage and somewhat less often thereafter. 
Organoleptic tests and chemical analyses were made of these samples.

ORGANOLEPTIC TESTS.
The following notes are compiled from the observations of W. A. Taylor, George C. Husmann, and W. N. Irwin:

	Tolman: A very dark brown juice, flavor sweet and lacking in acid, and therefore
	rather too insipid for use as a beverage. There was no particular character to the
	juice. It was moderately clear. When fermented considerably it was still very
	insipid and unpalatable.
	Winesap: Juice clear and thin; not up to the standard expected of the variety, lacking
	both sugar and acid. There was an off flavor, somewhat musty.
	Yellow Newtown: A fairly clear, well balanced, palatable juice. Slightly off flavor,
	and it was doubtful whether the tests were fair to this variety.
	Rails: Juice beautifully clear, but not up to standard, lacking in acid and distinctive
	flavor.
	Gilpin: Juice clear, but quite brown, standing next to Tolman in that particular.
	Heavy and sweet, but lacking in sprightliness and refreshing quality; had a
	good apple flavor and a fairly good aroma. It was improved by the slight fermentation
	noticeable after fifty days of storage.
	Baldwin: Juice clear, slightly astringent, but palatable and refreshing. At the end
	of forty-eight days a very slight trace of fermentation was noticed. At a period
	of eighty-six days this variety approached its maximum in quality for consumption
	as a sweet, slightly fermented cider. It was better than any of the above
	juices.
	Golden Russet: A beautifully clear, sweet, rich juice, possessing the cleanest and purest
	taste of any juice so far tried. After eighty-three days storage it was found to
	be very palatable, still rich and sweet and possessing enough "bite," due to the
	dissolved carbon dioxid gas, to be very palatable as a sweet cider.
	Roxbury Russet: Much browner and less clear than Golden Russet, but with an
	excellent apple taste and aroma. A heavy, satisfying juice, with a slight earthy
	taste such as is frequently found in Roxbury fruit as it approaches full ripeness.
	On examination after a period of forty-three days the earthy flavor was found to
	have almost entirely disappeared. While at this time it did not appear to be as
	sweet and rich as Golden Russet, which was tried at the same date, it was still a
	very rich juice. At the eighty-three day period, the juice was found to be still
	sweet, but to need a little more fermentation in order that its palatability as sweet
	juice should be at its maximum.
	Kentucky Red: Beautifully bright and clear, very light in color. Less heavy and rich
	than Roxbury and Golden Russet, but an exceedingly palatable juice. Less
	fruity in flavor than Roxbury Russet. A trace of fermentation was noted after
	eighty-three days, the juice being very palatable at that time.

CHEMICAL ANALYSES.
The chemical data secured are shown in Table II and are platted graphically in figures 1 to 9. Certain errors were 
introduced in collecting the data, due to varying conditions not at first noted, which can be avoided in future work, 
but no attempt has been made to correct the figures themselves, the data being published just as they were 
obtained. The formation of ice in the casks of cider which had been kept in the chill room led to the incorrect 
determination of the readings by the Brix spindle. This ice melted very slowly in the cider. As it loosened from the 
sides of the casks it -rose to the surface, and the water formed from the ice also probably remained near the 
surface. Fortunately, these facts were apparent before the Brix readings of March 24 and the analyses of April 8 
were made; and the contents of each cask was well mixed before taking the samples, except in the case of the 50-
gallon barrel of Baldwin cider. This barrel was well shaken by rocking, but the contents were not sufficiently 
agitated, as the Brix reading and other determinations made on April 8 are too low, with the exception of the 
sucrose, which was too high, probably due to analytical error.

In addition the charts show when the ciders were fermenting perceptibly and when they had fermented too far to be 
considered sweet. The corresponding intervals, together with the alcohol content of the ciders, are given in table III.

At the time of preparing the ciders 5-gallon lots of each variety, except Gilpin and Kentucky Red, were allowed to 
ferment spontaneously at laboratory temperatures in carboys previously well cleaned and kept stoppered during 
fermentation with clean cotton plugs. In all cases fermentation started promptly. The juices were practically
completely fermented in from thirty-three to fifty-four days.

DISCUSSION.
The striking fact brought out in this experiment is that the cider is kept in storage from thirty-six to eighty-three days,
an average of sixty-one days, before beginning to ferment noticeably. The average in the case of the first six 
varieties was fifty days. These varieties are mentioned separately because they are more typical of the usual 
American cider apples than the last three. The amount of alcohol developed

during this time varied from 0.40 to 1.65 grams per 100 cc, with an average of 0.8 gram. For the first six varieties 
the average was 0.5 gram. From ninety to one hundred and twenty-five days were required before the ciders had 
fermented too far to be called sweet, or an average of one hundred and seven days for all the varieties and of 
ninety-nine days for the first six. No deterioration in flavor during cold storage was noticed, except in the case of the
Tolman variety, which is hardly a cider apple. No perceptible injury in flavor resulted from the slight freezing to which
many of these ciders were subjected before they were finally stored at C. Not only were the characteristic flavors of 
the apples maintained, but an improvement was noted, due to the presence of carbon dioxid. The varieties giving
the highest grade ciders were Baldwin, Golden Russet, Roxbury Russet, and Kentucky Red.

The charts show graphically the changes in the composition of the juices during cold storage. In each set of curves 
the upper line is the reading of the Brix spindle at a temperature of 17.5 C. While for the fresh ciders this reading is 

practically equal to the content of total solid matter, in the fermented ciders it is merely useful in giving an idea of 
the progress of the fermentation. The total sugars remained practically constant during the first fifty days of storage
for all of the varieties studied. The low value found for the Baldwin variety on April 8 has already been explained as 
due to the formation of ice (see p. 4). After approximately fifty days the total sugar values gradually declined. The 
reducing sugars followed in a general way the course of the total sugar, but the rate of loss was less rapid, owing
to the fact that inversion of the sucrose was taking place. The total acid readings are nearly constant and show a 
gradual increase during the fermentation, the increase being largely due in all cases, except the Tolman variety, to 
a very slight formation of volatile acid. The Tolman variety shows a slight increase in acid, of which a considerable
portion was fixed acid. The rate of fermentation increased rather rapidly in all instances after about fifty days, but, 
on the whole, the changes were far slower than those occurring in common storage. As noted on page 6, the juices 
held at laboratory temperatures after pressing fermented rapidly, fermentation starting in all cases within a few days 

and being completed within thirty-three to fifty-four days. A number of points remain to be determined before 
definite recommendations can be made as to storing cider. These points include:
	(1) The influence of the number of yeasts and other organisms present on the storage of cider.
	(2) The development of methods for controlling this infection if it is found to be a serious factor.
	(3) The behavior of cider after its withdrawal from cold storage.

SUMMARY.
	(1) Ciders prepared from apples free from decay chilled rapidly to the freezing point immediately after 
	pressing, and  then held in cold storage at C. (32 F.) remained without noticeable fermentation for a 
	period of from thirty-six to fifty-seven days, an average of fifty days for the Tolman, Winesap, Yellow 
	Newtown, Rails, Gilpin, and Baldwin varieties, and of eighty-three days in the case of the Golden 
	Russet, Roxbury Russet, and Kentucky Red. .
	
	(2) These ciders were held for a period of from ninety to one hundred and nineteen days, an average 
	of ninety-nine days for the first six varieties and of one hundred and twenty-five days for the last three, 
	before they fermented sufficiently to be considered as becoming "hard" or "sour."

	(3) The ciders were found to have suffered no deterioration (with the exception of the Tolman), but 
	rather had become more palatable during storage.

End of Text


Return to the Self-Reliance or Alcohol & Vinegar page.

Please Read The Website Disclaimer!
Copyright 1986-2012, The Survival & Self-Reliance Studies Institute (SSRsi), All Rights Reserved
Site conceptualized, designed, created & maintained by MEG Raven
Snail Mail: SSRsi, PO Box 2572 Dillon, CO. 80435-2572