Often, yes. The bottle matters more than the brand. Choose a raw, unpasteurised, unflavoured kombucha with live culture, and you’ll give the new SCOBY the best chance. Pasteurised, preserved or heavily flavoured bottles are less likely to grow one, and results vary between brands and batches.
Check the label before you buy
Look for:
- “Raw” or “unpasteurised”. Pasteurising heats the drink, which kills the culture.
- No preservatives. Some bottles contain preservatives such as potassium sorbate, which can stop yeast from growing.
- Plain flavour. “Natural flavours” can hide almost anything, and essential oils can slow or stop the microbes you want.
Labels and recipes change, so check the bottle in front of you rather than relying on an old review.
What about GT’s?
GT’s is one of the best-known mass-market kombuchas, and many home brewers have tried to grow a SCOBY from it. The results are mixed. Some people report success, while others see little or no growth.
Check the current label for “raw” or “unpasteurised”. If the bottle is pasteurised or lists preservatives, try a different bottle first. If you do use a GT’s bottle, choose an unflavoured one, allow more time, and keep a backup plan, such as a bottle from a local brewer or a SCOBY from a friend.
Flavoured bottles: what changes
Flavoured kombucha is often made with fruit juice, herbs, spices or extracts. These can be lovely in the glass, but they make a poor start for a new SCOBY:
- Fruit juice adds sugar, which the culture can use, but it also changes the balance of the brew.
- Essential oils and herbal extracts may have antimicrobial effects that work against the culture.
- Preservatives and “natural flavours” make it hard to know what the bottle contains.
Some brewers do grow a SCOBY from flavoured bottles. The usual advice is to grow it in a plain brew first, then add flavour during the second ferment, in the bottle. Once you have a healthy SCOBY, flavour your batches as you like.
How to grow a SCOBY from a store-bought bottle
The method is the same as the full guide, with a few changes:
- Use 500 ml (2 cups) of unflavoured, raw kombucha as your starter.
- Make sweet tea from 250 ml (1 cup) of water, 15 g (1 tablespoon) of sugar and 1 black tea bag. Steep it and cool it to below 32°C (90°F).
- Pour the tea and the kombucha into a wide glass jar, cover tightly with a cloth, and set it somewhere warm (22–27°C / 72–80°F), undisturbed.
- Wait. A thin white film should appear within a week or two. It can take three to five weeks, or longer, to become a usable SCOBY.
For the full method and the reasons behind each step, see how to grow a SCOBY from scratch.
What to expect
- The first film can look see-through or patchy, or even a little like mold. Give it time, and check its texture and smell, not just its colour.
- The SCOBY may sink or sit at an angle at first. That is usually normal. See why does my SCOBY sink?.
- Brown strands hanging from the mat are yeast and are normal.
- Expect about 10 days in a warm spot, but three to five weeks is common at room temperature.
Fuzzy or powdery mold is a reason to throw the batch out. Is it mold or a healthy SCOBY? explains how to tell the difference.
If it doesn’t grow
- Wrong bottle. Pasteurised, flavoured or preserved bottles are a likely cause. Try another bottle, ideally raw and unflavoured.
- Too cold. Cool rooms slow growth. Move the jar to a warmer spot.
- Too little starter. Use the full 500 ml of bottle liquid.
- Too hot. Tea above about 35°C (95°F) can damage the culture. Let it cool before adding the kombucha.
- Still nothing after several weeks. Try a second bottle, or ask a local brewer for a SCOBY.
Keeping your new SCOBY
Treat your new SCOBY like any other. Keep it in starter tea at room temperature, covered, and feed it when needed. A spare SCOBY kept in a jar of starter tea is useful insurance. For storage and reuse, see our full guide.
How long can a SCOBY go without being fed?
Most guides suggest a few weeks at room temperature in starter tea, and some say up to a month. Check the liquid periodically. If it is nearly dry, top it up with a little cooled sweet tea or finished kombucha. For longer breaks, see how long a SCOBY can sit in starter liquid.