What You Need to Know
During fermentation, complex carbohydrates in rye bread are hydrolyzed to glucose, which is then converted by Lactobacillus plantarum to lactic acid and by Saccharomyces cerevisiae to ethanol and CO₂. The resulting mixture of acids, alcohol, and volatile compounds such as acetaldehyde, acetoin, and diacetyl gives kvass its characteristic mild sourness, slight sweetness, and subtle effervescence.
The Science
Primary Reaction
Simultaneous lactic acid fermentation and alcoholic fermentation of carbohydrates from rye bread