Kombucha Brewing Batch Calculator

How to calculate Kombucha Ratios?

Standard brewing follows a ratio of 10% starter liquid to 90% sweet tea. This ensures the environment is acidic enough to keep the culture healthy and protected from contaminants.

Starter = Total Volume × 0.10

Using the Kombucha calculator: an example

Let's look at how the math works for a standard 4-liter batch of kombucha.

Step-by-step calculation:

1. Measure 4L total volume.
2. Calculate 400ml of starter liquid (10% of the total volume).
3. Measure 200g of sugar and 20g of tea to be dissolved in the remaining water.

Frequently Asked Questions

Why is starter liquid important?

The starter liquid lowers the pH of the brew immediately, creating an acidic environment that prevents mold growth and harmful bacteria from taking hold.

Can I use honey instead of sugar?

Using honey is not recommended for beginners. Raw honey contains its own antimicrobial properties and bacteria that can compete with or weaken your SCOBY.

How long should I ferment?

Fermentation typically takes 7-14 days. The exact timing depends on the ambient temperature and your personal preference for sweetness versus acidity.