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Apple Cider and Its Preservation
Apple Cider and Its Preservation

Apple Cider and Its Preservation

by Frank E. Rice and Alton L. Markley, 1921 Cornell Extension Bulletin

Vitamins

A discussion of food values is not complete without a consideration of the content of those mysterious growth-promoting substances called vitamins. At the present time three are distinguished and for want of more detailed knowledge concerning them, they are designated as A, B, and C.

If the diet of an animal is lacking in any one of the three vitamins, no discomfort may be noted for some period of time, but later, symptoms will develop characteristic for the lack of each. Persons who have a large choice and use a variety of foods need not ordinarily fear those diseases which are caused by the lack of vitamins. On the other hand, it is entirely possible that there may be cases when, in the absence of any acute disease, the general health of a person may be poor because the vitamins in the diet are not quite sufficient.

Vitamins A and B are not so likely to be absent from the average diet as C. The first two are generally distributed in vegetables, cereals, meat, milk, and eggs, and they are not injured by cooking unless it is unusually prolonged. On the other hand vitamin C is found chiefly in fruits and is easily destroyed by heat. Green vegetables, sprouting seeds, and milk also supply this constituent. A person placed on a diet in which there is lack of C, develops the disease known as scurvy, the cure for which is simply the addition to his diet of foods high in that particular vitamin. Long before vitamins were thought of, or even before chemistry was a science, it was known that sailors, arctic explorers, and others who developed scurvy were rapidly cured by administering lemons, oranges, and many other raw fruits and green vegetables.

The destructive action of heat on vitamin C seems to be not so great in sour fruits as in more neutral media. For instance, the pasteurization of milk and the cooking or drying of cabbage and beans destroys nearly all of this vitamin, while orange and lemon juice may be boiled a long time, or even dried, and tomatoes may be canned at temperatures above the boiling point of water without great diminution of the scurvy-preventing element.

Chemical Composition of Cider

A green apple contains starch, and in the process of ripening all the starch becomes transformed into sugar. The following table shows how this change was found to take place in some apples which were analyzed.

StarchSugar
Very Green Apple4.14%8.03%
Green Apple3.67%10.51%
Ripe Apple0.17%14.51%
Overripe Apple14.07%

These results also bring out another important point: when apples are just ripe they contain the maximum amount of sugar, and over-ripening causes a reduction. It is, therefore, apparent that cider should be made from apples just as they are ripe; earlier or later, there will be less sugar in the juice. Furthermore, there is a smaller yield of juice from fruit that is overripe.

There is yet another disadvantage in preparing cider from green fruit; the starch which is there present passes partly into the cider and being in the form of very fine particles practically never settles out. Such cider then, is much more cloudy than that made from ripe apples.

A considerable quantity of malic and tannic acids are present in all apples. It is these that give the apples and juice the tart taste. It might be thought that the sweeter varieties are sweet on account of a greater amount of sugar, but this is not the case. Apples are sweet or sour depending on the amount of acids present. The color of the cider depends upon tannic acid. If the pulp be exposed to the air from twelve to twenty-four hours before pressing a darker color of the cider results. The action of the tannic acid together with the air causes darkening. Also, part of the cloudiness of cider is due to albuminous matter; tannic acid assists in precipitating this out and making it settle. Hence a juice high in this acid will be of a darker color and is more likely to be clear.

Winter and fall apples are superior to summer varieties for use in cider making; on the average, winter apples contain from 2 percent to 2 ½ percent more sugar than do summer apples. Cider made from fall or winter apples also retains its taste more perfectly after pasteurization.

TERMINOLOGY

In this discussion the terms cider, sweet cider, and apple juice, have been used interchangeably. When the apple juice has undergone yeasty fermentation and contains more or less alcohol, it is generally called hard cider. However, in foreign countries the term cider refers usually to the alcoholic product. Freshly pressed unfermented apple juice will continue to be referred to as cider.

PREPARATION of CIDER

As has already been pointed out, the apples should be put thru the cider mill when just ripe, for at this stage there is a maximum of sugar and a minimum of starch, both conditions being important in obtaining a high grade of cider.

The fruit should be sorted to make sure that no rotten apples are used. Decayed tissue bears a disagreeable taste and, in addition, always carries bacteria and molds which, when growing in the cider, cause a distinct lowering of the quality. Even removing the cores has been recommended by some, since the seeds carry substances that do not improve the taste of cider.

Washing of the fruit is rarely done, but a better product would result if such treatment were accorded. The wash water from the fruit will be found to have a very disagreeable taste and odor.

Apples which are kept off the ground before use, result also in the production of a better cider.

All parts of the equipment used in pressing the juice should be continually kept in good sanitary condition. Small parts, press cloths, and strainers should be boiled in water. If the condition of the apparatus is very bad, then a liberal use of a solution of bleaching powder, or of any one of the chlorinated soda preparations should be made.

The amount of cider that may be obtained from a bushel of apples may be variously estimated at from two and one-half to four gallons. The amount will, of course, depend upon the variety of fruit, its degree of ripeness, and still more on the efficiency of the cider press. Fresh apples contain from 80 percent to 86 percent water, but the best presses do not remove more than 70 percent to 75 percent of it.

CLARIFICATION of APPLE JUICE

Not only is it desirable to remove the heavy insoluble matter from the cider to improve its appearance, but also if the product is well clarified there will be fewer bacteria and yeast cells, and hence less difficulty will be experienced in preserving it.

Sedimentation and Filtration

Allowing the liquid to stand in vessels undisturbed will cause the heaviest particles to settle to the bottom; then the upper part may be easily drawn off. Some of the suspended matter, however, is of such extreme fineness that it would not settle in any reasonable time. Under such conditions, filtration will often accomplish much. The juice may be poured thru a flannel bag, or a milk strainer may be used with a layer of cloth, cotton, or paper pulp, in the bottom.

Heat

When cider is brought to a temperature between 130? and 170? F very much of the suspended matter will coagulate and rapidly settle out. This has the double effect of destroying bacteria, although it may be necessary to reheat later, if heat is to be depended on for preservation. One very common operation of handling cider is to heat the freshly pressed juice to about 170? F, allow to stand until the largest particles have settled, draw off from the sediment as cleanly as possible, and filter through cloth. If the juice is to be pasteurized later the temperature used must be five degrees less than on the first occasion; otherwise more material may separate at the second heating.

Passing Through a Separator

By passing the cider once or twice through an ordinary cream separator much of the material can be removed which causes cloudiness and which might later settle out.

Addition of Clarifying Materials

There are some substances which, when added to acid liquids such as fruit juices, are coagulated in large particles. While these large particles are forming, and during the time of settling, much of the finely suspended matter also is coagulated and made to settle out along with the added material. The following are some of the materials which have been recommended for use in clarification by this method:

Casein can be obtained in the powder form. It should be mixed up as a paste with water and added in the proportion of 1 ounce of the powder to 20 gallons.

Egg albumen does not coagulate readily unless heated to 180? F. If this be added in the same proportion and in the same manner recommended for casein and then the cider brought up to 180? F, much of the suspended matter will be coagulated along with the albumen.

Milk and blood have also been tried for this purpose, since these materials contain considerable amounts, respectively, of casein and albumen. However, not much success has been found in their use.

Any of these substances should be used only with great care and intelligence. After the addition, the cider should be filtered and preserved very quickly for, otherwise, bacterial action might start and disagreeable-tasting substances be formed.

Tannic and citric acid coming together will produce a flocculent precipitate. The following procedure had been used in Europe: Dissolve 3 ounces of citric acid and 1 ounce of tannic acid separately in a small quantity of cider. Add the former to 50 gallons of juice, mix, and then pour in the tannic acid solution, stirring until the solution is thoroughly mixed. Allow the juice to stand until well settled out; then filter.

Gelatine, isinglass (not mica), and other substances have been suggested for use in clarification. Any of these materials will give some benefit, though too much should not be expected.

PRESERVATION of CIDER

Bacteria, yeast, and molds are always present in the air. The skin of perfect fruit is well covered with yeasts. In decayed spots, in dirty fruit, in unclean containers and presses, all three types of organisms may be expected in large numbers. Any fruit juice, then, is to begin with, well inoculated with organisms which begin to multiply as soon as it is pressed.

Molds develop slowly and will only be in evidence when the juice is allowed to stand quietly in order that the moldy scum may develop at the surface. Molds cannot grow at all except where there is a free air surface. Bacteria are also slow in growing and are manifested chiefly by “off” odors and by cloudiness. The yeast, on the other hand, if let alone, begins to multiply at once, rapidly producing alcohol and a froth of gas bubbles.

The rate of growth of these organisms depends considerably upon the temperature at which the cider is kept. At the temperature of a living room this alcoholic fermentation is very rapid indeed, and it is necessary to hold the liquid below freezing in order absolutely to prevent action. The temperature of an underground cellar is not sufficiently low to keep cider sweet. The report of the following experiment is taken from The Rural New-Yorker. Cider was prepared from clean fruit with every sanitary measure observed, placed in a clean barrel and transferred to a room held at a temperature of from 40? to 50? F. The following are the results of analyses made for alcohol each day:

Age of Cider in Days1234567891011121314
Percent of Alcoholtrace.08%.08%.12%.19%.44%.61%.90%1.00%1.30%1.50%1.80%

In some observations made by the authors, cider held at room temperature fermented to more than 6 percent alcohol in six days.

Therefore, if cider is to be kept sweet it is necessary to destroy the yeast which is the cause of the development of alcohol, or to in some other way prevent those organisms from multiplying. In order to accomplish this, there are two general methods: (1) addition of chemical preservatives; and (2) heating the cider as in the pasteurization of milk.

Preservation with Chemicals

The impression seems to be general that the most common and best method of preserving fruit juice is with chemicals. This is not true. Chemical preservatives have in recent years been given much publicity but their use is not so extended as one might believe. Satisfactory results cannot always be expected and there are some very serious objections to their use.

Granulated sugar has been added to cider by some people under the supposition that it assists in keeping it sweet. In order to have any effect at all it would be necessary to add such a considerable quantity that the taste of the cider would be unpleasant and in addition such procedure would be very expensive. Sugar cannot at best have more than a very slight retarding effect and it will be found that after alcoholic fermentation does begin in such a mixture, it is more active than if nothing has been added.

Spices, especially mustard, have been suggested as preservatives. These also cannot be added in sufficient quantities to have more than a slight effect.

The perfect chemical preservative would be one which, when added to foods, prevents all bacteria from growing, does not in the least alter the taste or appearance of the food, and does not injure the consumer. No preservative is known which even approximates these conditions.

Molds grow most luxuriantly in the presence of air but not at all in its absence. Therefore, regardless of how cider is preserved it should be placed in containers which are entirely filled so that no air space remains. If air space is unavoidable, then mold growth can best be prevented by floating on the surface of the cider a layer about one-eighth of an inch thick of tasteless oil. Cottonseed oil or a colorless mineral oil are satisfactory. This procedure effectively prevents the air from reaching the surface of the cider and also the growth of mold.

Pasteurization

As has already been mentioned, the cause of changes in cider is always the growth of microscopic organisms – bacteria, molds, and yeast. And it is only when these are destroyed or held in check that preservation is certain. There is but one method of making sure that a food product will not change and that is, to subject it to such a high temperature that all life is destroyed, and then to prevent later recontamination.

The effect of strong heating, however, is to alter the flavor of most food products. For this reason it is not advisable to apply more heat than is absolutely necessary. Cider may be compared with milk in this respect; either can be surely preserved by boiling, but to most people the flavor of the boiled product is not good. However, by careful heating at lower temperatures, the keeping quality is imparted without greatly altering the taste.

Some bacteria are killed at comparatively low temperatures, while for others it is necessary to continue heating at a boiling temperature for a long time. For molds and yeasts, which are generally more easily destroyed, heating at from 145? to 150? F for an hour, or at about 180? F for a few minutes is necessary. The application of the higher heat for the shorter time has an equal effect on the microorganisms and on the flavor as if the product were exposed to the lower temperature for the longer time.

The pasteurization of cider, as with milk, is carried out by one of the two general processes: (1) heating at a comparatively low temperature for a long time – the “holding process;” (2) applying a higher temperature for a shorter time – “flash pasteurization.” The holding process is usually applied to bottles and jars filled with the product, while the latter treatment is used where larger quantities are to be preserved and held in larger containers. Flash pasteurization is often made a continuous process, the fluid being pumped or allowed to flow by gravity, thru heated coils; by the time it has passed entirely thru to the end, the liquid will have reached the temperature desired. From this point it is run into perfectly clean containers where it is held sealed to prevent the further entrance of the undesirable microorganisms.

Whatever the method of pasteurization, the liquid should be heated with as little exposure to air as is possible. When open to the air the heat drives out many of the volatile substances which impart the desirable flavors. When cider is pasteurized in bottles or fruit jars, therefore, they should be stoppered or capped throughout the process. Continuous pasteurization by passing thru a heated coil also retains these desirable substances. This is one of the reasons why the pasteurizing of cider in an open boiler or kettle is not so successful an operation. In addition, a “cooked” taste may be imparted thru excessive local heating such as the liquid is exposed to at the bottom of the container. However much the flavor of the cider is altered by heat, it is considered by most people to be a better product than that to which chemical preservatives have been added.

It must be borne in mind that if the liquid is pasteurized in one container and transferred into another, that the latter must be perfectly sterile and must be closed tightly after filling. Whenever there is exposure to the air recontamination by yeast and molds will take place, and unless the product is consumed at once, spoilage is sure to result. But if proper care is taken to use sterile containers, and if these are filled to the top and stoppered to keep out the air, the cider will keep sweet for an indefinite period of time.

Flash Pasteurization on a Large Scale

Perhaps it is most economical to pasteurize large quantities of cider by the continuous “flash” method. The juice flows from the press into a tank from which it is pumped or allowed to flow thru steam-heated coils of aluminum or copper and thence into barrels, casks, or bottles. If the cider is to be kept in casks with capacities of 10 gallons or more, the temperature of the outflowing cider should be about 170?F since the cider will keep hot for some time in the casks. But if it is to be bottled or put in fruit jars, or similar small containers, the temperature of the outflowing cider should be 175? F. In no case should it exceed 180? F or fall below 170? F.

Flash Pasteurization at Home

Flash pasteurization of smaller quantities of cider can be carried on in kettles or boilers heated directly over the fire. Quantities of a few quarts to several gallons can be treated in this manner. The cider is heated with continuous stirring until the temperature just reaches 180? F. The hot juice is then poured into sterile jars, or bottles which are filled completely full and tightly capped or sealed with sterilized caps. If it is desired to treat several gallons at once in this manner and to hold in casks, fill the sterile casks as full as possible, and if not full then, cover with a thin layer (1/8 inch think) of some tasteless, odorless oil, e.g., mineral oil or cottonseed oil which should also have been pasteurized. Then when the cider is drawn out at the bottom thru the spigot, and the air is admitted at the top, the air and the organisms it contains will not come in contact with the cider, which consequently will keep sweet and free from mold until entirely consumed.

Apple Cider and Its Preservation
Figure 1 – Bottle capper.

Holding Pasteurization

Pasteurization by “holding” is best accomplished in closed, small containers, such as capped bottles or sealed fruit jars. This method can be used on large or small scale. For small quantities, clean, but not necessarily sterile, pint or quart fruit jars, or bottles of the soda pop type are filled with the fresh juice. In the case of fruit jars the covers are clamped down tightly with rubbers. If bottles are used there can be obtained a hand capping device for stoppering (fig. 1), or corks may be used.

The bottles are placed in a boiler or large kettle of hot water. This container should have a false bottom or tray of screen and wooden slats so that there will be some little space between the bottles and the bottom of the kettle. This device permits a better circulation of the hot water and also prevents cracking of the bottles which would occur if the bottles stood on the bottom in direct contact with heat.

When the temperature of the water in the kettle reaches 185? F, lay the bottles in the kettle so that they are completely submerged. Keep a thermometer in one bottle full of cider which is standing straight up uncapped, with the top of it only an inch above the surface of the water. Continue to heat the kettle until the temperature of the cider in the center of the open bottle reaches 160? F. Do not stir with thermometer. When the temperature reaches this point lessen the heat of the bath somewhat and after the temperature of the cider has reached 165? F hold it at that temperature or slightly above for twenty minutes. The pasteurization is now complete and the bottles can be removed and allowed to cool gradually, and another supply of freshly filled bottles placed in the hot water, the temperature being noted as before.

If the temperature is held between 165? F and 170? F for twenty minutes the cider will keep sweet indefinitely. If good bottles and fruit jars are used, very little or no breakage will occur.

In factory practice, bottled cider is generally pasteurized in steam cabinets varying in size from that of a refrigerator to large rooms in which thousands of bottles are pasteurized at one time.

The temperature is controlled by an automatic device which permits live steam to flow around the filled and capped bottles until the desired temperature is reached. This temperature is then maintained for any desired period. Although ease and convenience in handling are the advantages of this apparatus, the initial outlay may not justify its use for small quantities of juice.

Apple Cider and Its Preservation
Figure 2 – Pasteurization in closed containers.

Flavor and Quality of Pasteurized Cider

In both the “flash” and “holding” methods of pasteurization the original quality of the cider is slightly changed. In the flash method, if the cider be exposed to the air, some of the volatile constituents which impart flavor and aroma to the juice, are probably lost, but in the holding method just described these are retained. After cider is pasteurized it cannot be filtered nor separated from the sediment and consequently it may be cloudy and not clear or “eye-bright.” It is claimed, however, that the suspended matter and sediment contain much of the food value of the cider and that no objection should be made to it by the consumer. It is not known just how much truth there is in this statement, but certainly if sanitary measures have been employed in the preparation of the product, the insoluble matter is not of a harmful nature.

APPLE SIRUP (syrup)

Apple sirup is a product of somewhat higher concentration than boiled cider. In its preparation certain substances are added for the purpose of removing the acids which would otherwise cause the concentrated juices to be very sour and also for the purpose of obtaining a clearer product. The following method for making apple sirup is recommended:

Add 5 ounces of powdered calcium carbonate to 7 gallons of apple cider. Powdered calcium carbonate (carbonate of lime) or, to give it its common name, precipitated chalk, is low-priced and harmless. Boil the mixture in a kettle or vat vigorously for five minutes. Pour the liquid into vessels, preferably glass jars or pitchers; allow to stand six or eight hours, or until perfectly clear. Pour the clear liquid into a preserving kettle. Do not allow sediment at bottom to enter. Add to the clear liquid one level teaspoonful of lime carbonate and stir thoroughly. The process is completed by boiling down rapidly to a clear liquid. Use density gauge or candy thermometer and bring the temperature up to 200? F. If a thermometer is not available, boil until bulk is reduced to one-seventh of the original volume. To determine whether the sirup is cooked enough test as for candy – by pouring a little into cold water. If boiled enough it should have the consistency of maple sirup. It should not be cooked long enough to harden like candy when tested.

When the test shows that the sirup has been cooked enough, pour it into fruit jars, pitchers, etc., and allow it to cool slowly. Slow cooling is important, as otherwise the suspended matter will not settle properly and the sirup will be cloudy.

A good way to insure slow cooling is to stand the vessels, full of sirup, in a bucket or a wash boiler of hot water or to place them in a fireless cooker. The white sediment which settles out during cooking is called “malate of lime” and is a harmless compound of lime with the natural acid of the apple. When the sirup is cooled, it should be stored in fruit jars, bottles, or jugs and crocks. Place the rubber end cap or cotton stopper or cork in position and tighten. Place the container in boiling hot water and sterilize for the length of time given below for the particular type of outfit used:

minutes
Water bath, homemade or commercial15
Water seal, 214º10
5 pounds steam pressure8
10 pounds steam pressure5

Remove jars and tighten covers. Invert to cool, and test the joints. Store for future use.