AND T reva C. Kintner and Margaret Mangel UNIVERSITY OF M ISSOURI AGRICULTURAL EXPERIMENT STATION J . H. LONGWELL, Dlredor BULLETIN 631 COLUMBIA, MISSOURI SEPTEMBER. 1954 VINEGARS and SALAD DRESSINGS TREVA C. KINTNER AND MARGARET MANGEL WHAT IS VINEGAR? the product will not spoil and can be stored at room Vinegar is one of the first acids which man used tempe~atures . Occasionally vinegars produced and in food preservation. The word itself comes from the stored lfi open barrels contain minute round worms French words "vin aigre" which mean sour wine. ~h5ch are called vinegar eels. These worms are barely Vinegar generates so readily in dilute solutions of VIsIble to the naked eye but are readily observed under e~hyl.,al~ohol, that even in biblical times the expres­ the mic.roscope. Vine~ar eels are easily killed by heat SIon wme gone sour" was used. The oldest known or sunhght and even If not destroyed have no detri­ vinegar was made from grapes. Today, vinegars are mental effect on the human body. However, in none made from natural fruits, vegetables, refined sugar of the bottled samples of vinegar that are heated and and grains. Grapes, apples, oranges, bananas, honey, sealed are these organisms found. Vinegar that has dates, raisins, pears, apricots, peaches, pineapple, sugar been stored for several years at room temperature does or molasses, malt infusion and dilute ethyl alcohol all lose some of its moisture and such samples may have h~ve been used t? produce vinegars. In addition, many an acid content of over 6 percent. wme and malt vmegars have herbs or seasonings add­ TESTS ON ACIDITY OF VINEGARS ed to give the vinegars distinctive and desirable fla­ The acidity of vinegar is measured by two meth­ vors. o.ds. T~e most c?mmonl.y used method is simple titra­ Most vinegar is produced as the result of two tlon wIth a basIC SolutIon and computation of the fe~~entatior: pr.ocesses. In the first, the sugar con­ grams of acid in 100 cubic centimeters. This is usually tammg solutlOn IS fermented, with the aid of enzymes referred to as percentage by weight. By law, all vine­ ~ound in yeast, int? ethyl alcohol. This takes place gar is required. to have an acid content of 4 percent m .the absence of aIr. In the second stage, bacteria or more by weIght. The second method of determin­ bnng about the fermentation of alcohol to an acid. ing the acid content is by measurement of the hydro­ Thes~ bacteria are found in the mother of vinegar, a gen ion concentration on the pH meter. This is re­ gelatlfious scum which floats on the surface of vine­ ported as the pH of the vinegar. gar. Exposure to air is needed for this reaction. Neith­ er reaction is complete so that traces of sugar, alcohol . Th~ rr:et~od of determining acidity by percent ace~IC. aCld 10 Vl?egar, ~easures the total acids present. and glycerol are found in vinegar. These substances ThIS 1Ocludes, 10 addItion to the acid itself, the acid plus the organic esters and salts add the flavor and salts. The pH method measures only the ionized acid odor that make highly desired vinegars. in vinegar. The lower the pH number the more ioniz­ Vinegar is also made from ethyl alcohol pro­ ed acid present and the more sour the product tastes. duced by wood distillation. This process yields an A vinegar with a higher percentage of acetic acid does acetic acid content as high as 40 to 50 percent and the not necessaril~ taste more acid because the salts pres­ product is diluted to produce a vinegar of around 5 ent have less 10fluence on taste. The difference in percent acetic acid. A distilled or acid vinegar with ionized and total acid can be calculated from the caramel flavoring added is sold in Missouri. It comes known pH and percentage of acetic acid, and reported in open barrels and is available only in states which as acetate. have no laws opposing the sale of compounded vine­ gars. !able 1 shows the pH and percentage of acetic aCld 10 the many samples of vinegar tested in the Food Vinegar is about 90 to 95 percent water with Research Laboratory at the University of Missouri. about4 to 6 percent acetic acid. Also present are the The salt present, computed as millimoles of acetate, o~ganic flavoring and coloring compounds. Because also is given in this table. The average pH of all the v10egar contains a minimum of 4 percent acetic acid, vinegars was 3.05 with a range from 2.64 to 3.25. The most acid vinegar tested was the distilled with an This bulletin is based in part o.n Department of Ho.me Eco.no.mics research project No.. 130 emitled "Studies o.n Urilizatio.n of Processed Foo.d and Foo.d average pH of2.74. The bottled cider and pear vine­ Improvers." gars had the least amount of acid with an average pH · STATION BULLETIN 631 3 TABLE 1 -- ACIDITY OF VINEGARS Acetate in pH Acetic Acid Millimoles Number Number Number Type of of of of Vinegar Description Samples Average Samples Average Samples Average % Cider Bottled 18 3.25 9 4.4 6 19.6 Open barrel 8 3.08 5 4.4 5 16.2 All cider 26 3.19 14 4.4 11 18.1 Wine Red bottled 6 2.87 6 5.1 6 10.9 White bottled 3 3.00 3 4.9 3 14.5 All wine 9 2.91 3 5.0 9 12.1 Malt Bottled 3 3.07 3 5.3 3 18.2 ..Beach Bottled 1 2:98 5.4 14.9 Pear Bottled 1 3.25 1 4.4 1 22.5 Apricot Bottled 3.10 5.0 1 18.2 Distilled Regular bottled 5 2.64 4 5.1 4 5.9 Sugar, open barre 1 3 2.80 2 ' 3.6 2 6.5 All distilled 8 2.74 6 4.6 6 6.1 All Vinegar s 49 3.05 35 4.7 32 14.2 of 3.25. All vinegars except four samples of open or pickled meats, vinegar is added chiefly because of barrel type met the legal requirement of 4 percent the specific flavor it gives to the products. During acetic acid, Five of the vinegars had acetic acid con­ hard times the early American plOneers often made tents of 5 percent or more. They were malt, peach, vinegar pies. Here, vinegar was substituted for the apricot, red wine and bottled distilled. The average non-available acid fruit. Probably the most universal of all vinegars tested was 4.7 percent acetic acid. The use of vinegar today is in salad dressings. Other acids acetate present in natural fruit or malt vinegars might be used but vinegar is prized for both its flavor ranged from 10.9 to 2.5 millimoles. The distilled vine­ and keeping quality. gars had a low mean acetate estimate of 6.1 millimoles Cider vinegar is the most widely used of all vine­ which indicated the distilled vinegar was low in salt gars. It is usually sold as a fairly standard bottled pro­ content. Most of the variation in flavor and color of duct. Tests made on cider vinegar in open barrels vinegars can be traced to differences in amounts of showed wide variation in acidity. Cider vinegar is very natural salts present in vinegar. acceptable because of its desirable flavor and odor. Distilled or white vinegar is cheaply made from a so­ USES OF VINEGAR lution of ethyl alcohol. There is no flavor except the Vinegar has been used since ancient times as a acid and this vinegar is colorless. Food manufacturers preservative. Today we prize it chiefly for the specific who prefer an inexpensive acid almost always use this flavor it imparts to dishes. The use of vinegar as a type of vinegar. preservative is still recognized in the manufacture of Grapes are used in the production of wine vine­ such foods as pickles, catsup, relishes, green olives, gar. Red wine vinegar is made by allowing dark color­ pickled onions, cauliflower and other vegetables, and ed grapes to ferment. Yellow or white wine vinegar fruits such as spiced peaches and crab apples. Also, is made by removing the skins or using white grapes. vinegar is added to many foods during preparation. Many types of herbs and seasonings are added to wine These include salad dressings, sauces, gravies, and vinegars on the market today. Malt vinegar is a dark, seasonings for vegetables. Vinegar changes the vis­ heavy, lemon-like flavored vinegar. Often it has tarra­ cosity of cream or evaporated milk so that it thickens gon seasoning added. It is used for fish sauces and and can be used as sour cream. chicken salads and can be used instead of lemon in The acid property of vinegar aids in tenderizing many dishes. Pear vinegar is quite dark yet similar in the connective tissue proteins in meat, such as veal. flavor and use to cider vinegar. Peach, apricot and Vinegar may be used to neutralize hard water and pineapple vinegars are pale yellow in color and are thus aid in lessening the cooking time of vegetables excellent in dressings for fruit salads. like beans. In meat dishes such as schnitzel, lindstrom, In the south, a vinegar made from the by-pro­ sauerbraten, Swedish meat balls, barbecued, deviled ducts of the sugar refining industry is made and sold 4 MISSOURI AGRICULTURAL EXPERIMENT STATION as sugar vinegar.