Bread Needed
135g
Sugar
120g
Time
24–36h
ABV
1.0%
3.3L
120g
4g
21
Estimated ABV: 1.0%
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Inputs
Result
Bread = 45g/L × 3L = 135g. Sugar = 40g/L × 3L = 120g. Water = 3 × 1.1 = 3.3L. Yeast = 1.3g/L × 3 = 3.9g ≈ 4g. Raisins = 7 × 3 = 21. Room temp with yeast: 24–36 hours. ABV = (40/50 × 1.5) × (30/36) = 1.0%.
Inputs
Result
Bread = 50g/L × 10L = 500g. Sugar = 50g/L × 10L = 500g. Water = 10 × 1.1 = 11.0L. Starter = 25g/L × 10 = 250g. Raisins = 7 × 10 = 70. Warm with sourdough: 18–28 hours. ABV = (50/50 × 1.5) × (23/36) = 1.0%.
Inputs
Result
Bread = 40g/L × 5L = 200g. Sugar = 30g/L × 5L = 150g. Water = 5 × 1.1 = 5.5L. Wild ferment: no added yeast. Raisins = 7 × 5 = 35. Cool + raisin method (1.5×): 54–72 hours. ABV = (30/50 × 1.5) × (63/36) = 1.6%.
The amount of bread depends on the type and your batch size. Traditional dark rye bread requires about 45 grams per liter of kvass. Borodinsky bread uses 50g/L for a richer flavor, while lighter pumpernickel uses 40g/L and white bread only 35g/L. For a standard 3-liter batch with dark rye, you need 135 grams (about 0.3 loaves).
| Bread Type | Grams per Liter | Per 3L Batch | Flavor |
|---|---|---|---|
| Dark Rye | 45g | 135g | Classic, malty |
| Borodinsky | 50g | 150g | Rich, aromatic |
| Pumpernickel | 40g | 120g | Strong, dark |
| White Bread | 35g | 105g | Light, mild |
Traditional kvass uses 30–50 grams of sugar per liter depending on desired sweetness. Light kvass uses 30g/L, medium (traditional) uses 40g/L, and sweet dessert-style kvass uses 50g/L. For a 3-liter batch at medium sweetness, that’s 120 grams of sugar. The sugar feeds fermentation and provides the characteristic sweet-tart flavor.
| Sweetness | Sugar per Liter | Per 3L Batch | Est. ABV |
|---|---|---|---|
| Light | 30g | 90g | 0.5–1.0% |
| Medium | 40g | 120g | 0.8–1.5% |
| Sweet | 50g | 150g | 1.0–2.5% |
Kvass fermentation takes 12–48 hours depending on temperature and method. At room temperature (72°F/22°C), yeast-based kvass ferments in 24–36 hours. Warmer temperatures (82°F/28°C) speed it to 12–20 hours. Wild raisin fermentation takes 50% longer. Kvass is ready when it tastes tangy with light carbonation.
| Temperature | Yeast Method | Wild/Raisin Method |
|---|---|---|
| 68°F / 20°C | 36–48 hours | 54–72 hours |
| 72°F / 22°C | 24–36 hours | 36–54 hours |
| 77°F / 25°C | 18–28 hours | 27–42 hours |
| 82°F / 28°C | 12–20 hours | 18–30 hours |
Active dry yeast is the easiest option: use about 1.3 grams (1/4 teaspoon) per liter. Traditional kvass uses sourdough starter at 25 grams (2–3 tablespoons) per liter, which gives a more complex sour flavor. The most traditional method uses only raisins for wild yeast, but it takes 50% longer and results are less predictable.
Kvass typically contains 0.5–2.5% ABV, making it a very low-alcohol beverage. The exact ABV depends on sugar amount, fermentation time, and temperature. Light kvass with 30g sugar/L fermented briefly may be under 1%, while sweet kvass (50g/L) fermented longer at warm temperatures can reach 2.5%. Commercially, kvass is classified as a soft drink in Russia.
Read our guide
Read our guide
Read our guide
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Last Updated: Mar 19, 2026
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