Kvass is an ancient Russian drink known and loved for well over a thousand years. There are numerous recipes of kvass, and the term if often used broadly to cover all sorts of fermented beverages. Commercially produced kvass has even made its way to the shelves of some of the supermarkets in the US. Note that kvass typically contains a small amount of alcohol produced by the fermentation process, a lower concentration than you find in beer. In Russia, it is often not considered an alcoholic beverage. Use your best judgment, however. Here is a simple recipe you can try at home to get started: