квас (kvas): from Proto-Slavic *kvȃsъ (fermented drink), ultimately from the Proto-Indoeuropean root *kwh₂et- (to ferment, to sour). Cognates include Sanskrit kváthate (to boil, to heat), and Latin cāseus (cheese).
Kvas is a fermented, slightly alcoholic beverage made from rye bread or flour with the addition of yeast, water, and sugar. Common additions for flavour include raisins, mulberries, lingonberries, and mint. It's a common drink in Russia, Ukraine, and Belarus, and elsewhere in Eastern Europe. The first attested mention is found in the Tale of Bygone Years, a 12th century chronicle detailing the history of the Rus' people. However, as with most recipes of this kind, its origins are likely much older, and evidence of beverages made by fermenting cereals dates well into the 2nd millenium BCE.
Making kvas is exceptionally easy and doesn't require much equipment. Rye bread or flour is boiled in water and left to rest for a couple of hours. The liquid is then strained into a jar together with sugar, yeast, and raisins, and then fermented up to five days. The resulting beverage is sweet-sour in taste, slightly carbonated, and with an alcohol content ranging from 1% to 2%. It's served cold and best enjoyed in the hot season.
Time to prepare: 1h (plus 2-5 days of fermentation)
Equipment: Large pot, large glass jar, straining/cheese cloth
Dish origin: Eastern Europe
- Water, 1.5L
- Rye bread, 300g (or 500g rye flour)
- Sugar, 80-100g
- Dry yeast, 10g
- Raisins (or any kind of dried berries), 10g
- 3 lemon slices (optional)
Before starting: use filtred water, or even bottled water. Clean your equipment really well, especially the glass jar.
- Boil water, toast the bread or flour until it's almost burnt, rinse the raisins with filtred water.
- Once the water is boiling, add bread/flour, raisins, and 2 lemon slices. Take off the heat and set aside for 3 hours.
- Remove all solids. Place a cheese cloth over your glass jar and strain the liquid. Carefully squeeze any pieces of bread that might remain.
- Add yeast, sugar, some more raisins, and a slice of lemon if you want. Mix well and seal the jar.
- Keep in a warm, dark place for 2 up to 5 days.
- Strain in a glass bottle using a cheese cloth and refrigerate for at least 24 hours before serving.
The ideal room temperature for kvas to ferment is 25°C, but anything in the range of 20°-32° will work fine. If fermenting for more than 2 days, open the lid for a couple of seconds every day to prevent too much CO2 from building up. Sugar can be substituted with honey (in which case cut the quantity in half), but this will result in more alcohol content as the honey will ferment as well. Blueberries, mulberries, and mint are a nice addition for extra flavour. Add them to the strained liquid before leaving it to ferment.