1919 Home made beverages

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Beverages

Alcoholic

wines contain the following substances: Propylic, butylic, caprylic and caproic alcohols; acetic and enanthic ether; grape sugar (dextrose and levulose); glycerine; gums; pectin; coloring and fatty substances; protein bodies; carbonic acid, ordinary and levo-tartaric and racenic acids; citric acid; malic acid; tannic acid; acetic acid; lactic acid; succinic acid; organic and inorganic salts. Of these the propylic and butylic, caprylic and caproic alcohols, the ethers, the glycerine, the carbonic, acetic, lactic and succinic acids are produced during fermentation, the remaining substances being original constituents of the grape juice, which also contains bitartrate of potash, but this being insoluble in weak spirit is thrown down or deposited as the conversion of sugar into alcohol proceeds. In its crude condition it is known as argol and is the source of cream of tartar and tartaric acid. As a result of its formation in the grape a considerable amount of the free acid is removed from the fruit. This is why wine made from grapes is so much superior and keeps so much better than that manufactured from fruits that abound instead in citric and malic acids. These latter require the addition of large quantities of sugar to disguise their acidity, a pro- ceeding which frequently gives rise in them to a second fermentation and often to the consequent formation of acetic acid. The acetic ether in wine is produced by the mutual reaction of acetic acid and ethylic alcohol. Neu- bauer, dissenting from Dupr6 and Thudichum, says the enanthic ether is the constituent to which wines owe their bouquet. He regards this ether as a combination of various substances of which caprylic and caproic acid ethers are the most important. Their formation is be- lieved to take place partly during and partly after fer- mentation. The rest of the non-volatile constituents, such as the sugar, the gum, the protein bodies, coloring matter, inorganic salts, etc., which remain behind when a wine is evaporated to dryness, constitute, with a certain quantity of substance the composition of which has not been defined, the extractive matter. 156