Quick answer
Brew a concentrated sweet tea with plain black or green tea and cane sugar. Cool it to room temperature, add starter tea and a SCOBY, and cover the jar. Ferment for about 7 to 10 days, then bottle it. A short second fermentation in sealed bottles adds fizz if you want it.
What you need (for one gallon)
- Water: 1 gallon (about 3.8 liters) of filtered or chlorine-free water
- Sugar: ¾ to 1 cup of plain white cane sugar (about 150 to 200 g)
- Tea: 6 to 8 plain black or green tea bags, or about 2 to 4 tablespoons of loose leaf
- Starter tea: 1 to 2 cups of plain, unflavored, unpasteurized kombucha
- SCOBY: 1 active SCOBY (the culture). If you don’t have one, see how to grow a SCOBY.
- Equipment: a 1-gallon glass jar, a tightly woven cloth or coffee filter, a rubber band, and glass bottles with tight lids for the second fermentation
Two notes on ingredients. The starter must be unpasteurized, because pasteurized bottled kombucha has no live culture to start a batch. And use plain cane sugar. Honey, artificial sweeteners and sugar substitutes do not feed the culture in the same way.
Step 1: Sterilize your equipment
Wash the jar, spoons, measuring tools and anything else that will touch the tea in hot, soapy water. Rinse well, then sanitize with boiling water or a food-safe sanitizer. Wash your hands before you handle the SCOBY.
Step 2: Brew a concentrated sweet tea
Heat about 4 cups (1 liter) of the water until it is hot. Stir in the sugar until it dissolves. Add the tea and steep for about 8 to 10 minutes for tea bags, or 10 to 15 minutes for loose leaf. Use a shorter time for green tea. Then remove the tea.
Pour the sweet tea into the jar and add the rest of the cool, filtered water to make one gallon.
Step 3: Cool it to room temperature
Let the tea cool until it is roughly room temperature, around 70 to 80°F (21 to 27°C). Hot tea can harm the SCOBY and the starter, so do not skip this step. Check the temperature with a thermometer if you have one.
Step 4: Add starter tea and the SCOBY
Stir in 1 to 2 cups of starter tea. Then gently slide the SCOBY onto the surface. It may float, sink or sit at an angle. All of these are normal.
Cover the jar with a tightly woven cloth or a coffee filter, and secure it with a rubber band. Do not use an airtight lid during the first fermentation, because the batch needs air and can build up pressure.
Step 5: First fermentation (7 to 10 days)
Keep the jar at about 68 to 78°F (20 to 26°C), out of direct sunlight. Start tasting around day 5, using a clean straw or spoon. The kombucha is ready when it tastes balanced, with some sweetness and some tartness. The longer it ferments, the tarter it gets and the less sugar it keeps.
Look at the surface as you go. Brown or stringy strands are normal yeast. A SCOBY can also become thicker over time. Fuzzy mold is different: if you see blue, black, green or white fuzzy spots, discard the whole batch, including the SCOBY, and start again with clean equipment.
Step 6: Bottle and carbonate (optional)
Lift out the SCOBY. Set aside 1 to 2 cups of the finished kombucha as starter tea for your next batch. Pour the rest into clean glass bottles with tight lids, leaving some headspace.
For fizz, add a small amount of fruit juice, fruit or herbs to each bottle, then seal it. Leave the bottles at room temperature for about 1 to 3 days. Open each bottle briefly once a day to release pressure, which is sometimes called burping. Once the carbonation is to your liking, move the bottles to the refrigerator to slow fermentation.
Sealed bottles can build enough pressure to break, so use bottles made for this purpose and do not overfill them.
Step 7: Save a SCOBY for your next batch
Store the SCOBY in a clean, covered jar with some of the finished kombucha in the refrigerator, where it goes dormant. When you are ready to brew again, bring it out, add fresh sweet tea and starter, and start over. A new, thin SCOBY often forms on the surface of the batch, and you can use it or pass it on.
Common mistakes
- Adding hot tea to the SCOBY. Let it cool first.
- Using flavored or herbal teas for the first batch. Use plain black or green tea.
- Using honey or sugar substitutes. Use plain cane sugar.
- Skipping the starter tea or using pasteurized kombucha. The starter brings acidity and live culture.
- Using an airtight lid during the first fermentation. Use a breathable cover.
- Using the wrong containers. Glass, stainless steel or food-safe plastic are the usual choices. Avoid ceramic that may be glazed with lead, and avoid reactive metals.
Safety notes
Homemade kombucha is less predictable than commercial kombucha. Its alcohol content can be higher, and contamination is more likely if you do not keep things clean. Follow the steps above, check for mold, and discard any batch you are unsure about. Is homemade kombucha safe to drink? covers the risks in more detail.
Kombucha is not recommended for everyone. Talk to a clinician before you drink it if you are pregnant, have a weakened immune system, have liver disease or take medicine that can interact with it. For more on this, see does kombucha clean the liver?.
Next steps
Once your first batch is done, you can try different bases. Start with the best tea for kombucha, then read how to steep tea for kombucha to fine-tune your brew.