Among the most ancient fermented beverages on record, documented in Eastern Europe for over a thousand years — the daily drink of peasants, soldiers, and farmers that turned stale bread into a nourishing, mildly fermented drink.
Ingredients (makes about 6 cups)
- 1 lb dark rye bread, ideally sourdough rye
- 2 quarts filtered water
- 2 tablespoons raw honey or brown sugar
- 1/4 teaspoon active dry yeast, or 2 tablespoons sourdough starter
- Optional: 1 tablespoon raisins
Method
- Slice bread thick and toast until very dark and dried, almost crouton-like.
- Place in a large heat-safe vessel. Bring water to a boil and pour over the bread.
- Steep, covered, 4 to 6 hours at room temperature until deeply dark.
- Strain through cheesecloth, pressing firmly, and discard the bread.
- Stir in honey or sugar while slightly warm. Cool below 80°F, add yeast or starter and raisins if using.
- Ferment loosely covered 12 to 24 hours until lightly bubbly. Strain and refrigerate.
Kvass is mildly alcoholic by nature — typically under 1% ABV. Eastern European folk medicine prescribed it specifically for fatigue and “weakness of the blood.” Refrigerate up to 5 days; flavor improves after 24 hours cold.
This recipe is one of twenty in The Forgotten Apothecary — our full digital cookbook of pharmacy-counter tonics, switchels, oxymels, and healing syrups.