Short answer: steep until strong, not bitter, then cool
Steep your tea until it is strong enough to give the culture something to work with, but not so long that it turns bitter. Then let it cool before the SCOBY goes in. Most of the mistakes that cause weak or harsh batches come from getting strength, temperature or cooling wrong.
Why strength matters
The tea is the base your culture feeds on. It provides nutrients, along with the sugar. A weak tea can lead to slow or uneven fermentation, and a thin-tasting finished drink. A harsh, overly strong tea can taste bitter and may make the batch harder to enjoy, even if the culture is fine.
Aim for a tea that is clearly flavored and a little darker than you would drink as a cup, without tasting harsh. Use the usual ratio of tea to water for your batch, as set out in how to make kombucha tea or the batch size table.
Water temperature by tea type
- Black tea can be steeped in near-boiling water. It is sturdy and handles heat well.
- Green, white and some oolong teas are usually brewed cooler, because hot water can make them bitter. Follow the packaging guidance for the specific tea.
- Pu-erh and other aged teas are often rinsed briefly with hot water before brewing. Check the specific guidance for the tea you use.
If you are unsure, start cooler and taste. You can always steep a little longer next time.
How long to steep
Steep times depend on the tea, the leaf size and the water temperature. For quick answers by tea type, see how long to brew tea for kombucha.
As a general rule, loose leaf needs more time than bags, and bags should be steeped for less time. Taste the brew as it steeps. Remove the leaves or bags once it is strong enough.
Loose leaf or bags
Loose leaf is usually a better choice for kombucha. The leaves are whole and unbroken, and they give a cleaner flavor. Bags often contain smaller pieces of leaf, which can extract faster and become bitter if steeped too long.
If you use bags, cut the steep time. If you use loose leaf, give the leaves enough room to open up, and strain them out when you are done.
Hot brew, then cool
Most brewers steep hot, then cool the sweetened tea to around room temperature before adding the SCOBY. Hot tea can harm the culture. Some brewers speed up cooling by using part of the water hot for steeping and adding the rest cold. Always check the temperature before adding the SCOBY.
Cold brew option
Some brewers use a cold brew, steeping loose tea in cold water for many hours, often 12 to 36. A cold brew is gentle and less likely to turn bitter, and the finished tea is already cold, so the cooling step is shorter.
Cold brew extracts more slowly, so the tea may be weaker. Use more leaf, taste before you add the culture, and keep the brew in the refrigerator if you steep it for a long time. This method suits brewers who want a forgiving, low-effort base.
Adjust strength by taste
Taste the tea before the culture goes in. If it is too weak, add more tea or steep a little longer. If it is too bitter, dilute it with cool water or use less leaf next time. Keep notes on the tea, the amount and the time, so you can repeat the batch that worked.
Common mistakes
- Steeping too long. Long steeps can make the tea bitter, especially with bags and green tea.
- Adding the SCOBY while the tea is still hot. Let it cool first.
- Using flavored or herbal teas as the base. Use plain true tea for the culture, and add flavorings later.
- Forgetting to remove the leaves or bags. Left in, they can keep extracting and turn the batch bitter.
- Using too little tea. A weak base can slow fermentation.
Bottom line
Steep until the tea is strong and pleasant, then cool it before adding the culture. Use loose leaf when you can, match the temperature to the tea, and taste as you go. A cold brew is a gentle alternative if you want a forgiving method.