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Transcript of MAKING VINEGAR
U.S. DEPARTMENT AGRICULTURE
FARMERS' BULLETIN No. 1424
IN THE HOME AND ON
illas "beon rv
binders at '' nd of f i l
T nXEGAR can l)e made Iroin any fruit, or, in fad, ' from any material wliich contains enough
sugar and is in no way ol)jectiona})le.
Whether it is done on a small scale in the home, on a larger scale on the farm, or on a still larger scale in the factory, the production of vinegar is the result of two distinct fermentation processesan alcoholic fermentation followed by an acetic fer-mentation.
By using the materials and following the methods (Uscussed in this bulletin, vinegar of good (luality may readily be made from apples, peaches, grapes, and ollur fruits, large quantities of which are wasted each vear in the I'nited States.
Washington, I) . C. Issiird June, 1924
MAKING VINEGAR IN THE HOME AND ON THE FARM.
By EDWIN LEFEVBE, Scientific Assistant, Microbiological Laboratory, Bureau of Chemistry.
Page, Vinegar 1 Mater ia l used, ~_ 2 Fermenta t ion 5 After t r ea tment 14 Causes of failure 10 Darkening of vinegar 21
Page. Animal paras i tes 22 Vinegar bees 23 Tests 2H Acid s t rength of vinegar 20 Federal regulat ions governing manu-
facture and sale of vinegar 28
V INEGAR was first made from wine, as its name indicates, at a remote period. Biblical writers mentioned it and Hippocrates used it as a medicine. By the sixteenth century vinegar from grapes was being produced in France for home consumption and for export. In England vinegar was lirst made fi-oin malt hquors, a method of disposing of ale and beer whicli had soured. For this reason it was ivuown us alegar. Although this name has long since become obsolete, malt vinegar is still the standard in the British Isles. I t is not known just when vinegar was first made in the United States, certainly very early as a home product. Here apple juice is largely used for this purpose and cider vinegar is considered tlie standard for household purposes. Other fruits and vegetables, however, are coming more and more into favor for making vinegar. Spirit vinegar, now manufactured in large quantities in the United States, is extensively used for pickling purposes. There are few homes in which vinegar in some form is not used for flavoring, pre-serving, or pickling.
Vinegar is essentially a dilute solution of acetic acid, made by ferinentation j)rocesses, containing salts and extracted matter. These additional substances, the exact nature and (luantity of whicli depend upon the material used, give the product its distinctive (piality. Sugar is the base of vinegar production. Any watery solution of a fermentable sugar may be transformed into vinegar under favorable conditions. Many fruit juices are Avell suit4>d to this purpose, as they contain sugar in the proper proportion and other necessary or desirable substances.
AH vinegar is made by two distinct biochemical processes, both of which are the result of the acticm of microorganisms. The first pro-cess is brought about by the action of yeasts wliich change the sugar into alcohol and carbon dioxide gas. This is the alcoholic fermenta-tion. The second process results from the action of a widely dis-tributed ^roup of bacteria which have the power of combining oxygen with the alcohol, thereby forming acetic acid. This is the acetic fermentation, or acetification.
2 Farmers' Bulletin U2i^.
The following recognized varieties of vinegar are classified ac-cording to the materitil from which they are made and the methods of manufacture: , , . ^. /. ^ i-
Vinegar made by the alcoholic and subsequent acetic fermentation of the juices of various fruits. Although apple juice is most com-monly used for making vinegar in the United States, other truit juices, notably those of grapes, peaches, oranges, persimmons, pine-apples, and some berries, are satisfactory. Any fruit or vegetable containing enough sugar will serve the purpose.
Malt vinegar made by the alcoholic and subsequent acetic termen-tati(m, without distillation, of an infusion of barley malt or other cereals in which the starch has been converted into maltose.
Sugar vinegar made by the alcoholic and subsequent acetic fermen-tation of solutions of sugar^ sirup, or molasses. ^ .
Corn-sugar vinegar made by the alcoholic and subsequent acetic fermentation of a solution of cornstarch sugar or of glucose prepared from cornstarch. , , , . . j . . i.- t
Spirit or distilled vinegar made by the acetic fermentation of dilute distilled alcohol.
M A T E R I A L USED.
Anything may be used for making vinegar, so long as it contains enougli sugar and is in no way objectionable. I t would be diiliciilt to describe in detail all the materials which are available tor this purpose. The following are most commonly used in the United States:
Nearly all varieties of apples contain enough sugar to make vine-gar of the required strength. This was well shown m three series of tests conducted by the Bureau of Chemistry on apples representing a large number of varieties grown during 1909, 1910, and 1911 m New York, Ohio, Virginia, Michigan, Missouri, and Washington. The average sugar content of the apples grown on grafted stock was found to be more than 13 per cent. In one series, including 5b varieties, in which two or more samples of each variety were analyzed (a total of 406 samples), the average sugar content was 13.34 per cent; in no sample was the sugar content less than 10 per cent, in a second series of 72 varieties, in which only one sample ot each variety was aualvzed, the average sugar content was 13.16 per cent; in only four of tbe varieties did the sugar content fall below 10 per cent In a series of 75 samples of seedlings, natural fruit, the average sugar content was 12.71 per cent, the sugar content of none of the samples falling below 10 per cent. , ^ ^ .
Winter apples have the highest and summer apples the lowest average sugar content, with fall apples intermediate. "mmer apples therefore are not suitable for vinegar making. Windtalf apples may well be used for this purpose, provided they are not from summer varieties and were properly matured at the time ot tailing. Green apples are incapable of yielding a satisfactory vinegar, be-cause much of their starch has not been transformed into sugar. Frosted or frozen apples have been used successfully for making
Making Vinegar. 3
vinegar, but they must be pressed soon after freezing and before any rotting occurs.^ Contrary to the usual belief, sweet apples are not richer in sugar than sour apples; in fact, some varieties may contain less than the average quantity. The sweet taste of these apples is due not to the presence of larger quantities of sugar but to a deficiency in malic acid, the acid normally present in apples.
Evaporated apple chops and the evaporated cores and parings obtained from apple-canning factories and apple-drying establish-ments are now used to some extent in the commercial production of vinegar. By passing water through several successive tanks of this material it is possible to obtain a sweet solution which serves for the production of vinegar. If the dried stock used for this purpose is clean and made from sound material, vinegar of satisfactory quality may be produced in this way. Such vinegar, however, is not made from the expressed juice of apples, so that when offered for sale it must be marked to show the material from which it is made.=^
Vinegar of unexcelled quality can be made from the grapes [Vihs mnifera) grown in Europe and on the Pacific coast of the United States. The white wine vinegar made from whole white grapes or from the pulp of purple or red grapes is excellent in quality. This must not be confused with what in commerce was formerly incor-rectly called " white wine vinegar," which is simply a spirit vinegar. Grape vinegar can compete commercially with cider vinegar only on the score of merit and if it is to be sold at a profit " it must be made in such a manner as to produce and preserve those qualities to which it owes its reputation for superiority over all other classes of vinegar "
Grape juice contains a very much higher proportion ot sugar than apple juice; hence a much stronger vinegar can be made from it. The California Agricultural Experiment Station has shown that a ton of California grapes (20 Brix) can give on an average 150 gallons of juice, which will yield 135 gallons of vinegar containing 9.8 per cent of acetic acid. The Bureau of Chemistry has shown that vinegar of excellent quality can be made from the muscadine o-rapes grown in the Southern States. Juice from four varieties of These grapes (16.5 Brix) gave by household methods vinegar which contained an average of 6.6 per cent of acetic acid.
The Bureau of Chemistry has shown that a very acceptable vinegar can be made from oranges, either on the household scale or on a commercial scale. Cull oranges will give a vinegar which not only is equal to the best grade of vinegar but can be made comniercially at a cost which in some markets permits competition in price with apple vinegar.
1A R Lamb and Edith Wilson. Vinegar Fermentation and Home Production of Cider" Vinegar. Iowa Agr. Exiit. Sta. Bui. 218 (lO'J.".). p. 5.
= TT S Dent. Agr., Food Inspection Decision 140 (l!tl2). F : T'. Bloletti. Grape Vinegar. Calif. Agr. Expt. Sta. Bui. 227 (1912), 26 pp.
4 Farmers' Bulletin iJt2^.
AVliile the average sugar content of peaclies is somewhat lower than that of apples, certain varieties contain enough sugar for vinegar making. Juicy varieties of the Carman type