Kombucha Calculator

Kombucha ingredient amounts scale linearly with batch size, so the water, tea, sugar, and starter liquid needed for a single gallon or a multi-gallon commercial batch follow the same ratios, just multiplied by volume.

Standard kombucha ratios per US gallon are 6 tea bags (or 12 grams of loose leaf tea), 160 grams of sugar (approximately 3/4 cup), and 240 milliliters (approximately 1 cup) of starter liquid. These scale linearly for larger or smaller batches, in either US gallons or liters. One SCOBY per fermentation vessel is standard regardless of batch size, since the culture does not need to scale with volume the way the other ingredients do. A SCOBY grows to fill whatever surface area its vessel provides over successive batches, which is why a five-gallon crock uses the same single starting culture as a one-gallon jar rather than five separate ones.

Tea format can be set to bags or loose leaf, which switches the tea quantity from a bag count to a weight in grams. Settings holds each ratio individually, tea bags per gallon (default 6), loose leaf grams per gallon (default 12), sugar grams per gallon (default 160), and starter liquid milliliters per gallon (default 240), so a recipe's own ratios can replace the standard ones, along with a step-by-step breakdown of how each ingredient amount was derived. Sugar amount matters beyond sweetness, since it is the fermentable food the SCOBY converts into the acids and trace alcohol that give kombucha its character, so cutting it well below the standard ratio risks starving the culture rather than simply producing a milder drink.

A 2.5-gallon batch at the standard ratios needs 6 x 2.5 = 15 tea bags, 160 x 2.5 = 400 grams of sugar, and 240 x 2.5 = 600 milliliters of starter liquid.

Kombucha recipes need to be planned and scaled with precision across a variety of brewing scenarios, serving homebrewers, commercial producers, educators, and fermentation enthusiasts who need reliable ingredient amounts for consistent results.

• Home Brewing: A standard one-gallon batch for a first kombucha brew uses the default ratios for a reliable beginner recipe: 6 tea bags, 160 grams of sugar, and 1 cup of starter liquid.
• Scaling Up Production: Transitioning from hobby brewing to commercial production means checking the proportionally scaled quantities for a 5- or 10-gallon batch to keep flavor and fermentation consistent across larger vessels.
• Metric Brewing: Liters work for international recipes or metric measuring equipment, with all ingredient amounts returned in grams and milliliters without manual conversion.
• Loose Leaf Tea Brewers: Calculating tea by weight in grams rather than bag count, and adjusting the grams-per-gallon ratio in Settings, matches the specific tea variety and desired strength of a brew.
• Recipe Experimentation: Customizing the sugar and tea ratios explores different flavor profiles: less sugar for a drier, more tart kombucha, or more for a sweeter starting brew, with preferred ratios saved for reuse.
• Educational Settings: Demonstrating fermentation science in classroom or workshop environments shows how ingredient proportions scale linearly with batch size, with the step-by-step breakdown illustrating the mathematical relationship between batch volume and each ingredient.
• Batch Planning: Fractional batch sizes such as 1.5 gallons or 2 3/4 gallons give precise amounts when working with non-standard vessel sizes or splitting a recipe to fit available containers.