![Brew Your First Kombucha, Start to Finish](https://cdn.slatesource.com/0/7/e/07ee4e0a-e9b5-4da7-aa35-fee7ab798d2d.webp) # Brew Your First Kombucha, Start to Finish - [Made in Slatesource](https://slatesource.com/@steph/brew-your-first-kombucha-start-to-finish) - By [Steph](https://slatesource.com/@steph) - Created on Oct 19, 2026 ## Kombucha is worth making at home Kombucha is sweet tea that a SCOBY (Symbiotic Culture of Bacteria and Yeast) turns into a tangy, lightly fizzy drink over one to two weeks. The process has two stages: first fermentation (F1) builds the base; second fermentation (F2) adds flavour and carbonation. A good batch takes 10 to 14 days of hands-off time and costs roughly a quarter per litre once the culture is established. The information you actually need is scattered. Official guidance gives you safe pH numbers on one page, contamination photos on another, and F2 ratios on a third. This page assembles the complete picture in one place. ![](https://cdn.slatesource.com/0/7/e/07ee4e0a-e9b5-4da7-aa35-fee7ab798d2d.webp) Photo by Shisma (CC0). A one-gallon jar of kombucha in active first fermentation. ## What you need before you start Equipment: a one-gallon (3.8 L) wide-mouth glass jar, a cotton cloth or breathable cover secured with a rubber band, a kitchen scale, a long spoon, swing-top glass bottles (16 oz / 500 ml) for second fermentation, and pH strips or a digital meter (optional but recommended for your first batch). Ingredients: 3.5 litres of filtered water, 7 to 8 black tea bags or 14 g loose-leaf, 200 g white cane sugar, and 350 ml starter liquid from a previous batch or from a bottle of raw unflavoured store-bought kombucha. Plus one SCOBY. Getting a SCOBY: buy one from an online fermentation supplier, get one from a brewer you know, or grow one from scratch. To grow from scratch: pour 350 ml of raw GT's Synergy original kombucha into a clean jar, cover with cloth, and leave at room temperature for two to four weeks until a thin pellicle forms on the surface. Water 3.5 L total (3 L boiling, 0.5 L cold to cool it down) Black tea 7 to 8 bags or 14 g loose-leaf Sugar 200 g white cane sugar (not honey, maple syrup, or raw sugar) Starter liquid 350 ml, about 10 percent of batch volume SCOBY 1 disc, at least 6 mm thick ## How to brew the first fermentation Make the sweet tea: bring 3 litres of filtered water to a boil, remove from heat, add tea bags, and steep for 8 to 10 minutes. Dissolve all 200 g of sugar into the hot liquid and stir until no granules remain. Pour in 0.5 litres of cold water to cool the batch faster. Wait until the tea is fully at room temperature before adding the SCOBY or starter liquid. Hot liquid kills the culture. Touch the outside of the jar: it should feel no warmer than your hand. Add the starter liquid first, then gently lower the SCOBY in. Cover with cloth secured by a rubber band. Do not use a sealed lid during F1: the culture needs air. Set the jar in a spot at 22 to 26 C (72 to 79 F), away from direct sunlight. Leave undisturbed for 7 days before tasting. Boil 3 L water, steep 7 to 8 tea bags for 10 minutes, dissolve 200 g sugar. 0% Add 0.5 L cold water. Wait until jar feels no warmer than your hand before continuing. Pour in 350 ml starter liquid, then lower the SCOBY in gently. Cover with cloth and rubber band. No sealed lid during first fermentation. Leave at 22 to 26 C for 7 days, then taste with a clean straw each day until the balance suits you. When the taste is right: remove SCOBY and reserve 350 ml liquid as starter for the next batch. ## The pH safety number to know Before you bottle, your kombucha should be at or below pH 4.2. That is the FDA threshold below which the brew is classified as non-potentially hazardous. At that acidity, Clostridium botulinum and most foodborne pathogens cannot grow. Check with a pH strip or a digital meter. A healthy culture typically reaches pH 3.0 to 3.3 by day 10, well below the safety floor. If yours is still above 4.2 after 14 days, add more starter liquid (up to 20 percent of volume) and wait another two to three days before testing again. Safe floor pH 4.2 or below before bottling (FDA threshold) Ideal drinking range pH 2.8 to 3.5 Strong starter zone pH 2.5 to 2.8 Over-fermented below pH 2.5, vinegary, use as starter or discard Under-fermented above pH 4.2, continue F1, do not bottle yet [KombuVault: complete F1 to F2 brewing guide](https://kombuvault.com/blog/complete-home-kombucha-brewing-guide-f1-to-f2?utm_source=slatesource) ## How to spot real mold versus healthy growth A SCOBY grows in unexpected shapes, sinks, floats, or splits. All of that is fine. What matters is surface texture. Healthy SCOBY: cream to tan or slightly brown, flat, gelatinous, and shiny when wet. Brown yeast strands hanging underneath are normal. A sinking old pellicle while a new one forms on top is normal. True mold: dry, fuzzy, or dusty texture. Circular patches that resemble bread mold or fridge mold, in blue, green, black, grey, or bright white. If you see anything fuzzy, discard the entire batch including the SCOBY and the liquid. Do not wash and reuse. Start fresh. [Freshly Fermented: mold vs healthy SCOBY guide](https://freshlyfermented.co.uk/instructions/is-this-mould-on-my-kombucha-scoby-a-clear-guide-for-home-brewers/?utm_source=slatesource) ## Second fermentation: flavour and carbonation Second fermentation (F2) is where the drink becomes fizzy. Sugar in the flavouring you add feeds residual yeast, which produces CO2 inside the sealed bottle. This is the step most tutorials cover vaguely, so here are the specifics. Fill 16-oz swing-top bottles leaving 2 cm (0.75 in) of headspace. Add your flavouring, seal the bottles, and leave them at room temperature for 2 to 4 days. Open one bottle daily from day 2 to check the fizz level (this is called burping). Once the carbonation is where you want it, refrigerate all bottles. Refrigeration slows fermentation and locks in the fizz. If a bottle feels hard to the touch before day 2, refrigerate it immediately. Excess pressure can crack glass. Always open over a sink. Fresh ginger 5 to 8 g per 500 ml bottle Fruit juice 30 to 45 ml per 500 ml bottle Fresh or frozen berries small handful, lightly muddled F2 at room temperature 2 to 4 days (burp from day 2) After refrigerating drink within 30 days Use swing-top glass bottles rated for carbonation. Ordinary mason jars and thin-walled bottles can crack under pressure. Never use a sealed lid on the F1 jar: the culture requires airflow during first fermentation. [Ferment Foundry: kombucha pH level guide](https://fermentfoundry.com/kombucha-ph-level-guide/?utm_source=slatesource)