How to cook
First, make the kvass - it's not hard but requires some time (just the first time)!
Knead the whole wheat flour with water in a jar using a spoon - the amount of water isn't that important (whether it's a bit thicker or runnier than a sludge isn't important). Leave the mixture at room temperature and keep an eye on it. If needed add more flour, if you add too much, add water - stir it every day.
After 7-10 days, the kvass will begin to rise. You'll see bubbles floating to the surface right after you stir it - it's a sign that it's ready.
Now it's time for the kvass bread - I used a bread maker but if you feel like spending a ton of extra effort you can knead it by hand (same proportions). Put the liquid ingredients and white flour in the bread maker, add 4 tbsp of the kvass you've made and turn the bread maker on the basic program, until it gives the signal that it's time to add the other ingredients.
After the signal, stop the bread maker and leave the mixture for at least 12 hours at room temperature. Once the dough has doubled in volume, it's ready to bake - turn it on the baking setting and bake for 1 hour.
It seems complex but it's a lot of fun watching what happens in the bread maker. A lot depends on the surrounding the temperature but the goal is the same - doubling of the volume.
I'll only talk about the taste and consistency of the bread with others who have made it - I never buy or bake bread any other way. My thanks to the lady who gave me the recipe for the kvass though!