Kombucha Batch Calculator
Enter your brewing vessel size and get the classic kombucha ratios - water, sugar, tea and starter liquid - based on the standard one cup sugar and eight tea bags per gallon recipe.
Results
- Tea bags
- 8 bags
- or loose leaf tea
- 14 g
- Starter liquid
- 490 ml (2.1 cups)
- SCOBY
- 1
One SCOBY per vessel regardless of size up to about 1 gallon; it adapts to the surface area.
Ranges found in published recipes: sugar 50-70 g/L, loose tea 3-5 g/L, starter 10-15% of volume. Longer brews and bolder tea sit at the higher end.
How the ratios work
Kombucha recipes scale linearly with water volume: sugar is about 5% of the water weight, tea about 2 bags per liter, starter liquid about 13% of the volume. The culture consumes roughly half of that sugar over a typical 7-14 day first fermentation, which is why finished kombucha still tastes tart rather than sweet.
Standard kombucha ratios
| Ingredient | Per liter | Per gallon (3.79 L) | Source |
|---|---|---|---|
| Sugar (1F) | 50–70 g | 1 cup (~200 g) standard | Crum & LaGory, The Big Book of Kombucha (2016); standard brewer recipes |
| Tea bags | 2 bags | 8 bags | Standard recipe (8 bags/gallon) |
| Loose leaf tea | 3–5 g | 14 g standard | The Big Book of Kombucha (2016) |
| Starter liquid | 100–150 ml | 2 cups (~500 ml) | Standard recipe (10–15% of volume) |
| SCOBY | 1 per vessel (any size up to ~1 gal) | The Big Book of Kombucha (2016) | |
For the sugar side in depth - including second fermentation and what ends up in your glass - read the kombucha sugar guide.
Frequently asked questions
How much sugar for 1 gallon of kombucha?
The classic recipe uses 1 cup (about 200 g) of sugar per 1 US gallon (3.79 L) of water - roughly 50-70 g per liter. The culture consumes about half of it during a 7-14 day first fermentation.
How many tea bags per liter of kombucha?
About 2 bags per liter (8 per gallon), or 3-5 g of loose leaf tea per liter. Black or green tea, or a blend, works best - the culture needs the nitrogen and tannins in real Camellia sinensis tea.
How much starter liquid do I need?
About 10-15% of the batch volume - roughly 500 ml (2 cups) for a 1 gallon batch. Use mature, sour kombucha from a previous batch or high-quality store-bought raw unflavored kombucha, plus the SCOBY itself.
Can I scale the recipe to any vessel size?
Yes - the ratios scale linearly with water volume, which is exactly what this calculator does. One SCOBY covers any vessel up to about a gallon; for larger vessels the same SCOBY adapts to the surface area.