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Kombucha brewing, explained from the culture up

Tools, ratios and fermentation guidance for brewing kombucha at home — organised by the stage you are actually at, with pH, temperature and bottling pressure taken seriously.

Browse the tool library Start with the recipe calculator

Everything here is free and works in your browser. Nothing is transmitted or stored.

A glass brewing jar of kombucha on a wooden table in natural light — original illustration

The library

Five stages, five sets of tools

Kombucha brewing splits cleanly into a handful of jobs. Pick the one you are doing right now.

How it works

Four steps from sweet tea to bottled kombucha

Every tool in this library is tagged with the steps above it applies to, so you never have to guess what a piece of equipment is for.

  1. Brew the tea — original illustration

    Brew the tea

    Brew sweet tea and let it cool

    Steep your tea for 8–12 minutes, dissolve the sugar while the water is still hot, then cool the sweet tea to below 30 °C (86 °F). Adding the culture to hot liquid damages it.

  2. Add starter & SCOBY — original illustration

    Add starter & SCOBY

    Add the starter liquid and the culture

    Pour in the starter liquid — the acidic, already-fermented tea — then float the pellicle on top. The starter does the real work of acidifying the batch; the pellicle is mostly a by-product.

  3. Ferment — original illustration

    Ferment

    Ferment at a steady temperature

    Cover with breathable cloth and hold roughly 20–28 °C (68–82 °F) for 7–14 days. Taste from day five and check pH with strips or a meter as it approaches 3.5.

  4. Bottle & flavour — original illustration

    Bottle & flavour

    Flavour, bottle and carbonate

    Add fruit, herbs or priming sugar, fill bottles designed for carbonated drinks, and leave them at room temperature for 1–3 days. Refrigerate as soon as the carbonation is right.

Read the full beginner's guide See all 30 tools

Start here

Ten tools that cover most of a first batch

If you are assembling a kit from scratch, these are the pieces that matter most, in roughly the order you will need them.

Browse all 30 tools

Free calculators

Do the arithmetic once, then repeat the batch

Consistent kombucha comes from consistent ratios. Each calculator runs entirely in your browser — nothing you type is sent anywhere.

Guides

Where most batches go wrong — and how to avoid it

Practical articles on pH, temperature, mould, carbonation and the ratios that make a brew repeatable.

Read all articles

Brew safely, and keep notes

The single best upgrade to your kombucha is a written record: tea and sugar weights, temperature, pH readings and tasting dates. It turns a lucky batch into a repeatable one.

pH & fermentation estimator How we write