Kombucha Sugar Calculator
Kombucha sugar, strength, and bottle count for any batch.
What it does
Kombucha starts as sweet tea, so batch math is sugar weighed over tea volume. This page turns those two inputs into total sugar, strength per liter or per gallon, and a bottle count at a standard 355 ml fill.
The metric default is 4 L with 280 g sugar. Strength is 70 g/L and the batch fills about 11.3 bottles. Imperial defaults convert the same batch to 1.06 gal with 9.9 oz sugar, giving 9.3 oz/gal and 11.3 bottles at 12 oz.
Strength is a taste and ferment choice. Mid 60s to 70s grams per liter brews balanced for many drinkers, higher doses finish sweeter and fizz harder in round two, and low doses can stall or turn sharp fast. Keep notes so repeats land the same.
This page does not judge safety or doneness. Starter share, temperature, days, and pH readings guide the ferment; sugar math only sizes the batch and the bottles to wash.
How to use
- Pick metric or imperial first (metric default).
- Enter sweet tea volume.
- Enter sugar weight.
- Read total first, then strength and bottles.
- Scale both inputs together to resize the batch.
Formula
- tea
- Sweet tea volume before culture.
- sugar
- White sugar weighed for the batch.
- concentration
- Sugar per liter or per gallon.
Sugar feeds the first ferment and leaves residual sweetness plus carbonation food. Strength is a starting choice, not a safety line: sanitation, pH, and time control the brew. Bottles assume 355 ml (12 oz) fills with small headspace loss ignored.
Worked example
Example: 4 L batch
4 L sweet tea with 280 g sugar (imperial 1.06 gal, 9.9 oz).
- Total: 280 g in 4 L.
- Strength: 280 / 4 = 70 g/L.
- Bottles: 4,000 / 355 = 11.3 bottles (355 ml).
- Imperial: 9.9 oz in 1.06 gal is 9.3 oz/gal.
- Tool shows 280 g, 70 g/L, 11.3 bottles (355 ml).
Reference table
| Strength | Sugar | Note |
|---|---|---|
| 50 g/L | 200 g | Light, drier finish |
| 60 g/L | 240 g | Balanced light |
| 70 g/L | 280 g | Common default |
| 80 g/L | 320 g | Sweeter start |
| 100 g/L | 400 g | Sweet, slow sour |
Limits
- First ferment sugar only. Second ferment adds more.
- Ignores headspace and spill loss in bottles.
- No pH or safety guidance.
- Honey and juice sugars differ by weight.
Common mistakes
- Measuring sugar by cups instead of grams.
- Scaling tea without scaling sugar.
- Reading strength as a doneness test.
- Forgetting starter tea in total volume.
- Capping weak bottles that still ferment.
Try it yourself
Quick checks. Answers sit tucked under each question.
2 L with 140 g sugar?
140 g, 70 g/L, 5.6 bottles (2,000 / 355).
5 L at 70 g/L needs what sugar?
350 g at 70 g/L (5 x 70).
Questions
How much sugar per liter?
Weigh it and divide by tea volume. Here 280 g in 4 L is 70 g/L.
How many bottles does it fill?
About 11.3 bottles at 355 ml each for a 4 L batch.
What is that in imperial?
Near 9.9 oz in 1.06 gal, or 9.3 oz/gal.
What strength is normal?
Often 60 to 100 g/L for first ferment. Less gives thin body, more leaves sweet finish.
Does sugar set sourness?
No. Culture, temp, and days set sourness. This page sizes sugar and bottles only.
Does it cover flavoring?
No. Honey, juice, and second ferment flavors sit outside this math.