Vinegar is an acid liquid produced by oxidation of fermented malt-wort, wine, cider, or other alcoholic liquid, by means of an organism, and consists essentially of impure acetic acid. It occurs as a brown or nearly colourless liquid, the colour varying according to its origin. Malt vinegar is the kind usually employed for medicinal purposes. It has a characteristic odour. Specific gravity, 1.017 to 1.025. Artificial vinegar is usually prepared by diluting acetic acid with water and adding burnt sugar or other colouring matter, the mixture being sometimes flavoured to imitate malt vinegar.
Constituents.—Vinegar should contain not less than 4 per cent. of acetic acid, but no free sulphuric acid, nor any other mineral acid. It should be free from lead, copper and arsenic. In addition to acetic acid, vinegar often contains traces of other organic acids, together with sugar, dextrin, colouring matters, and characteristic ethers; malt vinegar yields an extract containing a notable proportion of phosphates.
Action and Uses.—Malt vinegar has, to a slight extent, the action of the dilute acids. It is used as a cooling lotion for bruises and sprains, and as a domestic remedy for chilblains.
Dose.—4 to 30 mils (1 to 8 fluid drachms).