The SCOBY doesn’t just need sugar; it needs the minerals, nitrogen, and tannins found specifically in the tea leaf (Camellia sinensis). While it’s tempting to get creative, choosing the wrong tea can weaken your culture or cause mold. Here is the definitive guide to what works and what doesn’t.
š The Gold Standard: Black Tea
If you are a beginner, start here. Pure Black Tea (Ceylon, English Breakfast, Darjeeling) contains the highest levels of purines and tannins, which act as “bodybuilding fuel” for your SCOBY.
Other “Safe” Options
Verdict: Great, but mix it 50/50 with black tea for long-term SCOBY health.
Verdict: Good for floral flavors (like Elderflower), but produces a thinner SCOBY.
Verdict: A fantastic choice for advanced brewers looking for complex flavor.
Verdict: Fun occasional brew, but your SCOBY will turn permanently pink.
š« Teas to AVOID (The “Mold List”)
Using these teas in your First Ferment (F1) is the #1 cause of mold and weak cultures.
- ā Earl Grey / Chai: Contain essential oils (Bergamot/Clove). Oils coat the SCOBY and repel water, causing mold.
- ā Herbal Teas (Mint, Chamomile): These are not real tea (no nitrogen). The SCOBY will starve.
- ā Smoked Teas (Lapsang Souchong): The smoke oils can harm the bacteria.
*Note: You can use ALL of these in the Second Ferment (F2) for flavor, just not to grow the SCOBY!
ā 10 Common Questions
Can I use cheap tea bags (Lipton)?
Yes! Kombucha is not a snob. Cheap black tea bags actually work incredibly well because they are cut fine (dust), releasing lots of tannins quickly. You don’t need premium loose leaf.
Can I use Decaf tea?
Yes, but ensure it is decaffeinated using the Water Process or CO2 process. Chemical decaf (using ethyl acetate) can harm the bacteria.
Can I mix Green and Black tea?
Highly Recommended! This is the secret “Brewer’s Blend.” A mix of 70% Black and 30% Green gives you the health of the black tea tannins with the lighter flavor of green tea.
Why are flavored teas bad?
Chemical flavorings and essential oils are antimicrobial. They fight bacteria. Since your SCOBY is bacteria, flavored teas will slowly kill it.
Can I use Matcha?
No. Matcha is a powder, not a steep. The powder creates a sludge that sinks to the bottom, suffocating the yeast strands and creating a muddy brew.
What about Rooibos?
Rooibos is a legume, not a tea leaf. It lacks the nitrogen the SCOBY needs. You can brew it occasionally, but not every time, or your SCOBY will shrink.
Does the caffeine disappear?
Partially. The SCOBY consumes about 25-50% of the caffeine during fermentation, but the finished drink will still give you a mild buzz.
Can I use Pu-erh tea?
Yes! Pu-erh is fermented tea. It creates a very dark, rich, earthy kombucha. It produces a very healthy SCOBY.
Does organic matter?
It is better. Non-organic tea is often sprayed with fluoride and pesticides, which can inhibit fermentation over time. If you can afford organic, use it.
Can I switch teas between batches?
Yes. If you used Black tea last week, you can use Green tea this week. The SCOBY adapts quickly.
Do you love the taste of Earl Grey or Mint? Use them in the Second Ferment! Brew your SCOBY in plain Black Tea (F1), then remove the SCOBY, pour the liquid into bottles, and add a bag of Mint or Earl Grey tea to the bottle for 24 hours. You get the flavor without killing your SCOBY.
