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Food Values and Adulterations: Vinegar

Vinegar. Vinegar is usually made from cider, wine, malt, or spirits.

Much of the so-called "white wine vinegar" is made from spirits of alcohol. One method of detecting the source of a vinegar is to rinse out a tumbler with the sample and allow it to stand over night. The odor of the residue will enable one who is accustomed to these odors to detect the source of the vinegar. Another method is to evaporate some of the vinegar in a tea saucer over a teakettle of boiling water. The odor and taste of the residue left in the saucer are characteristic. From spirit vinegar the residue is very small in quantity and practically odorless.

To detect the addition of caramel to vinegar, add about two teaspoonfuls of fuller's earth to two ounces of vinegar, in a tall bottle of about five ounces' capacity. Shake vigorously, allow to stand a half hour, and filter. The first part of the filtrate should be poured through the filter a second time. Compare the color of this filtrate with the color of a sample of the vinegar which has not been filtered. This may be conveniently poured into another bottle of the same size as that containing the filtered sample. If the coloring matter is largely removed by filtration, this indicates that the sample has been colored with caramel. a Sulphuric acid has often been used as an adulterant of vinegar. To detect it, moisten a lump of sugar with the suspected vinegar and place on a saucer. Place second piece of sugar moistened with water on a second saucer, and put the two into a warm (not hot) oven. If the sugar moistened with the vinegar becomes brown to black after a short time, while the second piece remains white, the presence of sulphuric acid is indicated.

Sugar; Honey. -Artificial honey is sometimes made by the use of common sugar and glucose, which is flavored to resemble the natural product. To detect the latter, add to a somewhat dilute solution of honey at least an equal volume of alcohol and stir. The production of a white precipitate of dextrose, which finally settles to the bottom of the glass, indicates the presence of glucose. This test may also be applied to a solution of candy. Glucose is not, however, properly considered an adulterant in candy. To detect starch in candy, boil some of the solution, and after cooling add a few drops of a tincture of iodine. The production of an intense blue color indicates starch. White sugar, especially granulated, before the passage of the pure food laws, usually contained a little blue coloring matter, such as ultramarine. This may be detected by making a strong solution of sugar in a tumbler and allowing it to stand for several days. The blue coloring matter will finally settle to the bottom of the glass. If saccharin is added to candy or a food product, it may be detected by the test given under "Canned Vegetables."