Guides & Recipes

The same how-tos that live in the app, on the open web. Everything here is free — including the safety guide. If you're brand new, start with Kombucha Basics and read them in order.

1 · Kombucha Basics

What kombucha is, how the culture works, and what your part in it is. · 3 min read

What makes kombucha kombucha

Kombucha is sweet tea transformed by a living culture. Tea, sugar, culture, and time go in; a tangy, lightly fizzy drink comes out. What makes it kombucha — and not just sour tea — is the ferment: the culture eats the sugar and turns the tea into something new.

SCOBY and pellicle — what's what

SCOBY stands for Symbiotic Culture Of Bacteria and Yeast — the living community itself. It lives in the liquid, so your starter tea is the SCOBY: it's what actually starts every brew. The jelly-like mat that forms on top is the pellicle, a mat the bacteria build as they work — it grows on top because that's where the air is. It's a healthy sign, but it's optional — the liquid is the culture that matters.

Yeast, bacteria, and sugar — the team

Think of it as a relay. The yeast eat sugar first, making a little alcohol and carbon dioxide. The bacteria then turn that alcohol into acids. The bacteria need air for their half of the job — they're aerobic — which is why F1 ferments under a breathable cloth rather than a sealed lid: air gets in, fruit flies don't. Sugar is the fuel for the whole chain — which is why a brew starts sweet and turns tart over time, and why taste, not the calendar, says when it's done.

The acids are the bodyguards

Those acids do more than flavor the brew — they protect it. As they build, the kombucha becomes too acidic for most harmful microbes, which is what makes it safe to brew at home; a finished brew sits around pH 2.5 to 3.5. It's also why every batch starts with starter liquid: it brings the acid up from day one.

F1 and F2 — the two ferments

Brewing happens in two stages. F1, the first ferment, is where sweet tea becomes kombucha: an open jar with a cloth cover, about a week, tasting from day 5. F2, the second ferment, happens in sealed bottles with your flavors added. The yeast keeps producing carbon dioxide, and since the gas can't escape, the pressure forces it to dissolve into the kombucha — that dissolved gas is the carbonation. With no air in the bottle, the bacteria rest — F2 belongs to the yeast. Two to four days at room temperature, then into the fridge, where the cold helps the liquid hold onto it.

Your part of the job

The culture does the work; you keep the conditions right. Cover the jar, keep it somewhere comfortably warm, and taste as you go. Every number in these guides is a starting point, not a rule — your tongue makes the final call. Ready when you are: the first-batch walkthrough below takes you through it, step by step.

2 · First Batch Walkthrough

Everything you need to brew your first batch with confidence. · 5 min read

Gather your supplies

Have everything clean and within reach before you start. For one gallon: a 1-gallon glass jar (a wide mouth makes life easier); 2 cups of strong starter tea — that liquid IS the SCOBY, the living culture itself — from a friend's hotel or a trusted seller (a pellicle mat may come with it, but it's optional); plain black or green tea, about 20 g of loose leaf or 8 bags per gallon — unflavored, and with no added oils: F1 needs real tea for the culture to feed on, and oils can weaken it. Herbal teas are welcome later, in F2, for flavoring — but they shouldn't be the base of an F1; 1 cup of plain sugar; a gallon of water (if yours is heavily chlorinated, let it stand uncovered overnight first); a tightly woven cloth or coffee filters, plus a rubber band; and six to eight 16 oz swing-top bottles for F2, for when the first ferment tastes right. Two things worth saying twice: cover the jar with a tightly woven cotton cloth or a coffee filter — never cheesecloth, its weave is too loose and fruit flies get in — and treat the starter tea as the main event: it is the living culture that gets the batch going. The jelly-like mat (the pellicle) can go in too, but it is optional.

Brew the sweet tea

Heat 4 cups of water — how hot depends on your tea. Black tea takes a full boil. Green tea doesn't: boiling water scalds the leaves and pulls bitter, astringent flavors out of them, so for green tea (gunpowder included) aim for about 175–185°F (80–85°C). No thermometer? Boil the water, take it off the heat, and let it sit for 2–3 minutes. Steep the tea for 7 to 10 minutes, then stir in the sugar until it fully dissolves. Top up with 10 cups of cool, filtered water so the tea reaches room temperature.

Add starter

Only add your starter once the tea is below 85°F (30°C) — wrist-test it: neutral to slightly cool on the inside of your wrist is right; distinctly warm is too hot. Pour the starter in, then lay the pellicle on top if you are using one. Lay it on with clean tongs or gloves — never bare hands. It may sink or float; both are perfectly fine.

Cover and wait

Cover with a tightly woven cotton cloth, secure it with the band, and keep the jar somewhere warm (72 to 79°F, 22 to 26°C), out of direct sun. Cooler is safe too — fermentation will just take longer. Leave it undisturbed for 7 to 12 days.

Taste from day 5

Slip a straw under the pellicle and taste. When it is pleasantly tart with a hint of sweetness, it is ready for bottling or a second ferment.

3 · F2 Flavoring & Carbonation

Add flavor, build fizz, and make it your own. · 3 min read

Choose your bottles

Use thick, pressure-rated round swing-top bottles — square bottles have weak corners that can crack under pressure. Leave about 1 inch (2.5 cm) of headspace at the top.

Add flavor

Use 10 to 15% fruit or juice per bottle. Fresh ginger, berries and citrus give the most fizz because they bring extra sugar.

Seal and ferment

Close the bottles tightly and leave them at room temperature for 2 to 4 days. Warmer rooms carbonate faster.

Burp and chill

Open one bottle over the sink on day 2 to check pressure. Once it is fizzy enough, refrigerate everything to stop fermentation. Don't be surprised if the start of a pellicle forms in your bottle — it's harmless and totally normal; just strain it out when you pour.

4 · Continuous Brewing

Keep the brew going for a steady supply of kombucha. · 3 min read

The vessel

Use a ceramic, glass, stainless steel, or food-grade plastic dispenser with a plastic or stainless spigot. Glass, ceramic, and stainless hold up best over the long haul. Food-grade plastic works too — plenty of brewers use it — but it's the less durable option: cleaning scratches it over time, and scratches give unwanted bacteria places to hide where sanitizer can't reach, which can spoil batches. If you brew in plastic, clean gently with a soft cloth — never anything abrasive — and replace the vessel once the inside is visibly scratched. Other metals are out: they can corrode or react with the acid. Cover the top with a tightly woven cloth or a coffee filter, secured with a band — the brew needs air, but fruit flies stay out.

Drawing off

Every 3 to 7 days, draw off about a third to a half of the kombucha from the spigot for bottling — but never more than three-quarters. The mature brew you leave behind is your starter, and its acidity protects the fresh tea you add.

Refill

Replace what you took with sweet tea of the same strength, cooled below 85°F (30°C) first — wrist-test it. Hot tea can damage the culture.

Housekeeping

Every few months, remove extra SCOBY layers and some of the yeast sediment so the brew stays balanced.

5 · SCOBY Hotel Care

How to store, feed, and care for extra SCOBYs. · 3 min read

Setting up

Keep 2–3 spare pellicles in a clean glass jar, covered with strong, mature kombucha. Handle them with clean tongs or gloves — never bare hands, which can pass oils and germs to the culture. The liquid is what you are really keeping — it is your starter for future batches. Cover with cloth just like a regular brew.

Feeding

Every 2 to 4 weeks, pour off about a third of the liquid and top up with fresh sweet tea. Log each feed so you know who is hungry.

Keep it at room temperature

Never refrigerate a hotel. Cold slows the culture and makes it vulnerable to mold.

Sharing

A healthy hotel produces new layers quickly. Peel them off to start new batches or give them to friends.

6 · Is This Mold?

Learn what's normal, what's not, and when to worry. · 3 min read

Normal

Brown stringy yeast strands, clear or cream jelly-like patches, bubbles trapped under the pellicle, and uneven, bumpy new layers are all healthy.

Mold

Mold is dry, fuzzy and raised, in circles of white, green, blue or black. It always grows on top of the pellicle surface, never inside it.

What to do

If you see mold, discard the whole batch, including the starter and the pellicle. Clean the jar with hot water and vinegar before starting again.

Prevention

Use enough strong starter liquid (pH 4.5 or lower at the start), keep the brew warm, and keep the cloth clean and dry.

7 · Troubleshooting

Find solutions to common kombucha problems. · 4 min read

Too sweet

Let it ferment longer, or move the jar somewhere warmer. Taste every day or two.

Too vinegary

Ferment for fewer days next time. You can still use very sour kombucha as starter liquid or salad vinegar.

More or less sugar

More sugar means a sweeter start and more fuel for the culture — given time, it turns more tart, not sweeter. Less sugar ferments milder, can taste thin, and gives weaker fizz in F2. Start from about 1 cup (200 g) per gallon and adjust in small steps — roughly ⅛ cup at a time — tasting as you go.

No fizz

Use tighter bottles, add a little more fruit or sugar during F2, and keep the bottles warm for an extra day.

Fruit flies

Use a tightly woven cloth instead of cheesecloth, and secure it firmly with a band.

The house recipes

The three proven recipes from Don's brew log — the same starter flavors built into the app. Amounts are per gallon of finished kombucha; the app scales them to your batch, per bottle or per whole batch.

Amounts are starting points. Your taste, your batch — adjust, and write down what you actually did.