Kombucha Sugar Calculator

About this calculator

Kombucha fermentation needs a fixed sugar-to-water ratio for the SCOBY (symbiotic culture of bacteria and yeast) to have enough food to convert into acids and a small amount of alcohol — a commonly used starting point is roughly one cup of sugar per gallon of sweet tea base, though the exact rate varies with fermentation time, temperature and the tartness you're aiming for, so it scales linearly with batch size rather than staying fixed.

Home kombucha brewers use this calculation whenever they scale a recipe up or down from the batch size it was originally written for — going from a 1-gallon jar to a 5-gallon batch, for example — since getting the sugar amount wrong either starves the SCOBY culture or leaves the finished brew too sweet and under-fermented.

This calculator takes your batch volume and your chosen sugar rate, and returns the total amount of sugar to dissolve into your sweet tea base.