KVASS — Russian traditional low alcohol drink, product unfinished lactic and partly spirit fermentation of a grain must.
The industry several grades are issued To.: grain, Moscow, okroshechny, etc. Depending on a grade, conditions of preparation, fermentation and storage structure To. very labilen. It contains 93 — 98,5% of water, 0,21 — 0,58% milk to - you, 0,04 — 0,09% acetic to - you, 0,3 — 1,2% of alcohol, 0,03 — 0,35% of carbonic acid, 0,2 — 0,4% of nitrogenous substances, 0,26 — 5,21% of sugar, 0,3 — 0,8% of dextrins, 0,1 — 0,2% of mineral substances. Besides, To. contains vitamins, enzymes. In ready To. the small deposit of grain supplies and yeast is allowed.
In kvass normalize density on a sakharometra (1,5 — 7,3), acidity (2 — 4 ml 1 N of solution of alkali on 100 ml To.), content of alcohol (0,3 — 1,2%); shelf life at t ° 20 ° 3—4 day. Because of high acidity and content of carbon dioxide gas K. is Wednesday, adverse for reproduction of pathogenic microorganisms. Duration of preservation in it typhus and dysenteric bacteria, a cholera vibrio, colibacillus varies of several hours to 1 — 2 days. Damage To. there is from the use of substandard raw materials, non-compliance a gigabyte. governed at production and it is shown usually by development of collateral fermentations (acetic, butyrate). See also Soft drinks .
Bibliography: Hygiene of food, under the editorship of. K. S. Petrovsky, t. 2, page 277, M., 1971; D. A. Queens. Russian kvass, M., 1967
V. A. Kudasheva.