Kvass is a traditional Belarusian recipe for a classic drink made from lightly-fermented rye bread liquid. The full recipe is presented here and I hope you enjoy this classic Belarusian version of: Kvass.
Place the bread in a baking dish then put in an oven pre-heated to 150°C and bake for abut 20 minutes, or until the bread is dark brown and crisp.
Transfer the bread to a bowl, pour the boiling water over the top then cover and set aside in a warm place for about 4 hours. At the end of this time dissolve the yeast in about 200ml lukewarm and stir-in the sugar, mixing well.
After the four hours is up strain the bread mixture through a colander lined with muslin or cheesecloth, retaining the liquid. Stir the yeast mixture into this liquid then cover the bowl and set aside in a warm place to prove for about 10 hours.
Strain through cheesecloth once more then transfer the liquid into clean bottles. Add about 2 raisins to each bottle, cork and set aside in a cool day for 3 days to mature.
In Russia this is a classic 'soft' drink; it's also used as an ingredient in many soup recipes.