For the preparation of yeast kvass at home typically used yeast, bread crumbs and sugar. Kvas is a very ancient drink. The first prototypes, representing a middle ground between kvass and beer, have appeared in Egypt in 3 Millennium BC, describe very similar to kvass drink were also made by Hippocrates, Herodotus and Pliny the elder.
The alcohol content in the kvass is so small that you can drink even for children. Usually contains from 0.5% of kvass up to 3% alcohol (depending on manufacturer).
Kvas is a traditional Slavic beverage with volumetric fractions of ethyl alcohol not more than 1.2%, manufactured as a result of the unfinished alcoholic and lactic acid fermentation of wort. There are a variety of fruit and berry varieties of kvass: pear, cranberry, cherry, lemon, and others. Kvass in this genus represent or ordinary bread kvass, mixed with juice or jam from berries and fruits mentioned, or prepare directly from berry juice, without adding the bread or flour. It has a pleasant refreshing taste, improves metabolism, has beneficial effects on the cardiovascular system.
Kvass has excellent taste; It quenches thirst thanks to acid-dairy and it partly acetic; has high energetic value, promotes digestion due to carbonic acid contained in it, which facilitates the digestion of food and its intake and increases appetite. Chemical study of kvass, besides testing its taste, color, smell, is to identify: specific gravity, free carbonic acid, total acids and volatile acids, alcohol, extract, ash, protein and sugar.