Dry bread kvass

Dry kvass is the easiest to buy in the store. However, it is very easy to cook it at home. To do this, take rye bread (because there is malt in Borodino bread, it is better to take it).
1. Finely dice the bread and dry it in the oven. Make sure that the bread does not burn.
2. Interpret the baked bread in any way.
3. Now add rye malt, rye flour, calcined barley.
This will become the basis of kvass. It can be varied to your taste: add rice, buckwheat, also calcined, spices and herbs.
You can make real kvass from it.