Fermentation Friday: How to culture a SCOBY from a commercial bottle of kombucha

kombucha starterIt’s quite easy to culture your own SCOBY (symbiotic culture of bacteria and yeast) from commercial kombucha.  You will need to begin with a bottle of kombucha that is raw, unfiltered, unflavored & fresh.  Look for floaties or a mass in the bottles and choose the bottle that has the most.  My friend Jen found a bottle that had 2 mini scobys in it – mine (show above) had more of a loose ropey clump.  The easiest variety for me to obtain in NYC was GT’s Enlightened Organic Raw Kombucha.  I successfully cultured from this brand, as have four of my friends.

The basic how-to:

  1. Bring your bottle of kombucha to room temperature.  Clean some kind of wide-mouth glass jar for the culture.  I also sanitized mine with Star San because I had it but this is not necessary.  I bought my glass jar from a local discount store for around $2.
  2. Make sweet black tea.  I used a ratio of 1 cup of black tea: 1 tablespoon of sugar for this batch.  I used loose black tea as that is what I had at hand, using just over a tablespoon tea to the cup of water.  It is best to use black tea for this process – you can experiment with different varieties once you have a SCOBY.
  3. Cool sweet tea to room temperature, pour into glass jar and add your bottle of commercial kombucha.  Place muslin, a couple of layers of cheesecloth, or other fabric on top and secure to jar (I used a rubber band).
  4. Kombucha loves temps in the 70℉-80℉ range and it doesn’t like sunlight.  I placed mine in the warmest area of my apartment with an old t-shirt wrapped around it.  Now you just have to wait…

SCOBY formingThis was my SCOBY culture at 2.5 weeks.  Mine grew quite slowly as my apartment was a bit cool – under 70℉ most of the time.  The weather, and my apartment, warmed at 3 weeks in and my SCOBY took off.  From everything that I’ve read and my own experience, temperature is the primary determining factor in rate of growth.

SCOBYThis is my finished SCOBY.  It took me around 5 weeks to get a sizeable culture – again, this is temperature dependent.  It took less time for my friends’ cultures but their apartments are warmer.  Everyone I know that has attempted to culture SCOBY from GT’s was successful, but if your culture develops fuzzy mold or starts smelling bad in a non-kombucha way, toss it out and start over.

I haven’t yet brewed a batch of kombucha from my cultured SCOBY but plan to do so in the next week.  I’ll post my kombucha experiences & experiments in future Fermentation Fridays.

The Cultures for Health website has some great resources for kombucha making – articles, recipes, videos and a fantastic free e-book that can be downloaded when you subscribe to their e-mail list.  I highly recommend the e-book – it has everything that you need to know about brewing kombucha and then some.  Cultures for Health is a fantastic resource for all kinds of fermentation knowledge.

My absolute favorite kombucha is from Kombucha Party in Williamsburg.  Their kombucha is sparkling and less acidic than others that I have had.  And the flavors of the tea and/or ingredients really shine – the Silver Needle Jasmine is my favorite but every kombucha that I’ve tasted from them is lovely.  Stop by Pure Luck Tea Bar on 439 Metropolitan (on the north side next to the BQE b/w 5th St & 6th St) the next time you’re in Williamsburg & sample some of their kombuchas – they are truly delicious.

Happy weekend!


  1. Jessi from the Blog said:

    Hi Mary: Thanks so much for this post. I’ve been on a DIY kick lately, but hesitant to brew my own kombucha, though I’ve been averaging a 12oz. bottle every 2 days- which I’m sure you’re aware is quite pricey in the City. I’ve finally decided to give it a try and was hunting around for some local SCOBY- but if I can make it myself from what I normally purchase, I’m doing it! Thank you for this post.

    July 5, 2016

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