Kombucha beer is finished kombucha that you ferment a second time with beer or wine yeast and extra sugar. The yeast turns that sugar into alcohol, which gives you a sparkling, tart, lightly alcoholic drink instead of the trace-alcohol kombucha most people buy. You can make it at home with basic equipment, but a batch that builds pressure can break glass or spray over the kitchen, so the safety steps matter as much as the flavor.
This guide covers what kombucha beer is, what you need, each step from base batch to bottle, how sugar sets the strength, and how to fix common problems. For exact quantities, see the kombucha ale recipe. For the math on strength, see how much alcohol is in homemade kombucha beer.
Some brands and blogs use “kombucha beer” to mean a blend of beer and kombucha, like a shandy. This guide covers the fermented version, where you turn a batch of kombucha into an alcoholic drink.
What kombucha beer is (and how it differs from beer)
Kombucha starts as sweetened tea fermented by a SCOBY, a symbiotic culture of bacteria and yeast. The yeast turns sugar into ethanol and carbon dioxide. Acetic acid bacteria then convert most of that ethanol into acetic acid, which gives kombucha its sour bite. That is why ordinary kombucha stays low in alcohol.
Kombucha beer reverses that balance. You take the SCOBY out, so the acid bacteria can no longer convert the alcohol. Then you add an alcohol-tolerant yeast and more sugar, so the yeast makes ethanol instead.
Beer is brewed from malted grain, usually with hops. Kombucha beer is brewed from tea and sugar, and it contains no malt unless you add some. Its flavor is tart and tea-forward, closer to a sour or wild-fermented ale than to a lager.
Can I add alcohol to my kombucha?
Yes. Adding yeast and sugar to finished kombucha is the standard way to do it, and it is what this guide walks through. Keep two things in mind:
- Plain kombucha already contains a trace of alcohol. Adding yeast and sugar raises the level, often by a lot.
- Once a batch is alcoholic, treat it like any other homebrewed alcohol. Homebrewing for personal use is allowed in many places, but the rules vary, so check local rules before you brew, share, or sell.
If you want to keep alcohol as low as possible, see how to brew non-alcoholic kombucha instead.
What you need
- A base batch of finished kombucha. A gallon (about 3.8 L) is an easy size to start with.
- A food-safe fermenter with a lid, and an airlock that fits it.
- A no-rinse sanitizer made for brewing, plus a clean funnel or siphon.
- Fresh ale or wine yeast. Dry yeast is the easiest to store and use.
- Plain table sugar.
- A hydrometer and a tall test jar. The hydrometer is what lets you estimate the alcohol.
- A pH meter or pH strips (optional, but useful).
- Pressure-rated PET bottles with screw caps, and room in the fridge.
- Safety glasses for opening carbonated bottles.
Step 1: Start with a finished base batch
Brew a regular batch of kombucha first. Make sweet tea, cool it, add your SCOBY and some starter liquid, and cover the jar with a cloth or coffee filter so air can reach the culture. Let it ferment until it tastes tart with only faint sweetness. At room temperature, that usually takes one to two weeks, depending on how warm your kitchen is and how sweet you like it.
A pH meter helps you confirm the batch is acidic. A reading below about 4.5 is a common sign that the base is ready to move on.
Step 2: Remove the SCOBY and keep it
Lift out the SCOBY, along with any loose film. Store it in a clean, covered container with about 2 cups of your finished kombucha. It will serve as the starter for your next base batch. For how long it can wait, see how long a SCOBY can sit in starter liquid.
Removing the SCOBY matters. If you leave it in, the acid bacteria in it keep converting ethanol into acid, which works against the alcohol you are trying to make.
Step 3: Add fresh yeast
Pick an alcohol-tolerant yeast. Common choices include:
- Safale US-05, a neutral American ale yeast with a clean flavor.
- Red Star Premier Cuvée, a champagne yeast that gives more lift and fizz.
- Lalvin D47, an alcohol-tolerant wine yeast. The Zymurgy hard kombucha recipe uses it.
Rehydrate dry yeast as the packet says, because steps and temperatures vary by strain. Then stir it into the batch.
Kombucha is acidic, and yeast often starts slowly in acidic liquid, so brewers usually add more yeast than they would for beer. For a gallon, about 5 g of dry yeast (roughly one packet, or about two teaspoons) is a common starting point. Use fresh, active yeast, and be ready to wait a little longer for it to get going.
Step 4: Add sugar
Sugar feeds the new yeast, and the amount you add sets the ceiling on how much alcohol the batch can make. Dissolve table sugar in a small amount of boiled water, let it cool to room temperature so it does not harm the yeast, and stir it into the batch. Table sugar works well, so there is no need for specialty sugars.
As a rough rule, each 100 g of sugar (about half a cup) per gallon can add around 1.4% ABV, if the yeast ferments all of it. The full math and a sugar table are in how much alcohol is in homemade kombucha beer.
Step 5: Seal and ferment
Seal the fermenter with its lid and airlock. A sealed, low-oxygen setup favors the yeast and keeps the acid bacteria from working on the alcohol. Keep the batch at a steady temperature within your yeast’s range. Zymurgy gives 59–68°F (15–20°C) for D47, a common ale-yeast range. Use the range printed on your own yeast’s packet.
Take a hydrometer reading after the sugar is stirred in and before the yeast goes in. That is your starting gravity. Take another reading when airlock activity slows, and again a few days later. When the reading stops changing, fermentation is done. Fermentation usually takes around one to two weeks.
Use a hydrometer, not a refractometer. Once alcohol is present, refractometer readings are unreliable, so they can’t tell you when a batch has finished.
Step 6: Flavor it (optional)
Add flavorings near the end, once the batch tastes close to where you want it.
- Herbs and spices add flavor with little sugar. Steep them for a day or two, then strain them out.
- Fruit, juice, and purées add sugar. That means more fermentation and more pressure. Use small amounts, and count the added sugar in your strength estimate.
- Dry hops add aroma and bitterness. Keep the first batch light.
Step 7: Bottle and carbonate
Bottle in PET plastic bottles made for carbonation. Glass is common in homebrewing, but a bottle holding an active batch under pressure can shatter. Plastic lets you check the pressure by hand.
Fill each bottle with about an inch of headspace, cap it, and leave it at room temperature. Check the bottles often for the first day or two, because the yeast may still be active. Squeeze each bottle. A firm bottle means it is carbonating. A rock-hard bottle means it is close to too much pressure. Chill any bottle that gets very firm, then open it slowly over a sink while wearing safety glasses.
Once the bottles feel firm, move them to the fridge. Cold slows the yeast and bacteria but does not stop them, so keep the batch cold and drink it reasonably soon.
How strong will it get?
Strength depends mainly on how much sugar you add and how fully the yeast ferments it. Yeast strain and temperature matter too. How much alcohol is in homemade kombucha beer shows the math and how to measure your own batch with a hydrometer.
Troubleshooting
Nothing happens after you add yeast. Check that the yeast was fresh and rehydrated as the packet says, and that the batch is within the yeast’s temperature range. Acidic kombucha can slow yeast, so give it more time. If there is still no activity after a week or two, a fresh dose of yeast is the next step.
The finished batch is too sweet. Let it ferment longer, and check the hydrometer. Next time, use less sugar.
It is too strong or too dry for your taste. Use less sugar next batch. Chilling slows fermentation, so you can move the batch to the fridge once it reaches the sweetness you want.
Bottles gush or feel rock-hard. They are over-carbonated. Chill them, open them slowly over a sink, and use less sugar or fruit next batch.
Fuzzy mold or a rotten smell. Discard the batch. Do not taste it to check.
Safety and the law
- Use PET bottles, check them by hand, and wear safety glasses when you open them.
- Sanitize everything that touches the batch after the base is finished.
- Keep alcoholic batches away from children.
- If you are pregnant, in recovery, or taking medication that interacts with alcohol, talk to your clinician before you drink homebrew.
- Check local homebrewing rules before you brew, share, or sell.
Where to go next
Once you have the process down, the kombucha ale recipe gives exact quantities for a one-gallon batch. If you would rather keep alcohol minimal, read how to brew non-alcoholic kombucha.