How to Grow a Kombucha Scoby — in just 10-12 Days

Homemade KombuchaUsing six key concepts, we’ve developed a terrific method for growing a Kombucha scoby from a bottle of store-bought brew.

Kombucha is the delicious fizzy, probiotic tea that is becoming an increasingly popular DIY project. With store-bought bottles running $3-5 each, the cost savings for home brewers add up quickly. The key to brewing at home is obtaining a scoby, the pancake-shaped cellulose home for the Kombucha microbes. If you don’t have a friend nearby who can give you a fresh scoby, it’s easy to grow your own. The process is similar to creating a sourdough starter or establishing a home yogurt culture from a store-bought cup of yogurt.

The accurate temperature control of the Proofer makes it simple to speed the process of creating a scoby without risking damage to the culture from overly warm temperatures. It works, and it works much faster than the standard 3-4 weeks of other methods.

Six Key Concepts for Optimal Kombucha Scoby Growth

1. Culture the Kombucha at 80 °F / 27 °C.  The normal range for Kombucha brewing is 72-80 °F / 22-27 °C. Even though we might not choose to brew at 80 °F / 27 °C once our culture is up and running, it is the perfect temperature for speeding up scoby formation without danger of damaging the culture. Note:  temperatures below 72 °F / 22 °C carry an increased risk of mold contamination.

2. Pick a good location.  A good location is one where your Proofer can hang out for 10-12 days without being moved. The scoby will form on the surface of the kombucha, which means that if you jostle or swish the container the fledgling thin scoby could detach from the vessel walls and move below the surface. If that happens, your culture will start building a new scoby at the surface and you’ll end up with two super-thin pancakes instead of one thicker one. The Proofer should also be away from direct sunlight.

3. Use a 1-gallon container 8″ / 20 cm high or less.  Kombucha scoby formation works best with a high surface to volume ratio.  This means putting a relatively small amount of Kombucha in a large, wide container. For convenience, we chose the same one gallon glass container that will become our regular brewing vessel once our culture is up and running. An added benefit is that our first scoby will already be the right size for our brewing vessel. One widely available container that fits the bill is Anchor Hocking’s Heritage Hill 1-gallon jar / 4 L. The lid is not used.

If your container is taller than 8″ / 20 cm, it will not fit in the Proofer. 

4. Feed the culture, but not too much.  The bottled kombucha used to start the culture will not have enough glucose and tea nutrients for optimal cellulose production — a light meal is what your culture needs.  If you feed it too much, the culture will be too dilute and the scoby will take longer to form. If you don’t feed it at all, cellulose production will also be slow due to lack of nutrients.  Our recipe feeds the culture at a ratio of 2:1.

5. Use black tea.  Don’t experiment with green or white tea, a thick scoby forms best from regular black tea. For our tests we used organic English Breakfast tea and got great results.

Kombucha bottle with scoby

Kombucha bottle with a floating strand of culture

6. Choose a likely candidate.  For your starter bottle of store-bought Kombucha, choose an unflavored bottle of raw, unpasteurized brew. And if at all possible, find one with strands of culture floating in the bottle. Not only is a strand of culture a sign of healthy microbial activity, but strands that move to the surface during culturing develop faster than the rest of the culture.  (See photo of culture formation — the thicker, brighter white area is where the strand from the bottle was.)

Printable Recipe          recette imprimable

Yield: One kombucha scoby.

Timing: About 1 hour preparation and 10 days incubation in the Folding Proofer.

Ingredients

By Volume U.S. Weight
Raw, unflavored Kombucha* 2 C / 500 ml 500 g /16 oz
Filtered water, divided 1 C / 250 ml 250 g / 8 oz
Black tea bag 1  2 g / 0.07 oz
Sugar, white or organic white 1 T 15 g / 0.5 oz

*Ideally with a floating strand of culture (see photo).

Equipment:  Brød & Taylor Folding Proofer, one gallon / 4 L non-metal brewing vessel no more than 8″ / 20 cm tall, tightly woven fabric or paper cover and rubber band. An instant-read thermometer can be helpful for making sure the tea has cooled adequately.

Kombucha scoby formation

Scoby formation at six days. The dense white patch at the upper right is from the floating strand of culture that was in the bottle of Kombucha.

Get Ready.  Clean your brewing vessel and rinse the inside with white vinegar. If using a thermometer, also rinse the probe with vinegar. Set up the Proofer out of direct sunlight and where it won’t be disturbed. Set it to 80 °F/ 27 °C and allow it to preheat.

Make the Tea.  Measure out about one quarter of the water (¼ C / 60 ml) and bring it to a boil. Stir in the sugar to dissolve, then add the tea bag. Steep for 20 minutes. Remove the tea bag and add the remaining ¾ C / 190 ml of the water.  Check the temperature of the tea, making sure that it is below 90 °F / 32 °C. Note:  it is important that the tea be cool enough to avoid damaging the live culture.  

Feed the Culture.  Pour the cooled tea into the one gallon brewing vessel and add the bottled Kombucha. Cover the container with a paper or cloth cover held in place with a rubber band. Set in the Proofer and culture for 10 days.

11 day-old scoby

11 day-old scoby

Check on Your Scoby.  After ten days, open the Proofer and allow it to air out (it will have the “funky” aroma of Kombucha). Gently, without jostling your brewing vessel, remove the cloth or paper cover and check on the scoby. If it is still transparent or paper-thin in areas, you may decide to cover it back up and leave it a few more days.

During the ten-day culturing period, it’s fine to open the Proofer and check on the scoby periodically, just be careful not to jostle the container and dislodge the newly forming scoby.

Your First Batch of Kombucha.  When the scoby is ready, the Kombucha beneath it will be quite tart and vinegary. Use your new scoby plus 1-2 C / 250-500 ml of the tart Kombucha to start your next batch. You’ll have 1-2 C / 250-500 ml of sour Kombucha left over — for most people, this will be too sour for drinking as is. It can be used for salad dressings, or store it in the refrigerator and use it in place of vinegar to rinse out your brewing vessel before each batch.

If you’d rather try bottling it, make up some lightly sweetened tea and dilute the tart Kombucha to taste with the tea before flavoring and bottling.

Ginger and Strawberry Kombucha

2017-05-12T14:11:35+00:00 Fermented Foods|22 Comments

22 Comments

  1. alan lynn August 3, 2014 at 2:47 am - Reply

    I found Kombucha a couple months ago and am experimenting with different flavors

    • alan lynn August 3, 2014 at 2:48 am - Reply

      also milk and water kefer they are good also

      • Julie August 3, 2014 at 11:10 pm - Reply

        Our test kitchen is gearing up to perfect a kefir recipe, happy to hear you like it!

    • Julie August 3, 2014 at 11:10 pm - Reply

      Glad you’re having fun exploring flavors! Some of our favorites here are pear-lime, ginger-lemon, orange and sour cherry. Do you have favorites?

  2. Robin April 15, 2015 at 5:10 pm - Reply

    I am curious why you recommend using only black tea? Is this just for growing the scoby? Or for making batches too? I have been brewing (and selling) booch for awhile, and I have super good tasting batches made from 2/3rds green tea and 1/3 black. It has a less bitter taste and it is mellow where when I used black, it was super bitter and too strong.

    • Julie April 18, 2015 at 1:42 pm - Reply

      We recommend using all black tea for growing the scoby, because black tea will produce the fastest cellulose growth. Other teas will work for growing the scoby but will be slower. Once the first scoby is formed and the culture is up and running, any unflavored white, green, oolong or black teas will work beautifully. Staff favorites here are oolong and green teas 🙂

  3. Cat Ong August 14, 2015 at 12:24 am - Reply

    Thanks for sharing, I hope I also can grow my own Kombucha scoby one day.

  4. Julie August 17, 2015 at 12:59 pm - Reply

    Good luck!

  5. Yvette June 2, 2016 at 5:20 pm - Reply

    I am impatient and just began growing a scoby, actually two. In one batch I used all black tea in the other I used 2/3 black and 1/3 green tea and that one seems to me that the one in all black tea are growing the scoby faster. I check on my scobys daily, i can’t help it. It has been 2 days only and I see speckles of white translucent bacteria formation and bubbles already in the all black batch, in the green tea/black tea combo scoby I see bubbles but no speckles of bacteria yet.

    • Diane January 28, 2017 at 1:06 am - Reply

      Yvette, Thank you for your interest and we hope your results improved to success. We recommend using all black tea for growing the SCOBY, because black tea will produce the fastest cellulose growth. Other teas will work for growing the SCOBY but the growth will be slower and the SCOBY may be different (e.g., green tea SCOBYS tend to be thinner but are perfectly healthy). Once the first SCOBY is formed and the culture is up and running, any unflavored white, green, oolong or black teas will work beautifully. For more information about making kombucha see: https://brodandtaylor.com/kombucha-faq/ Let us know if we can be of assistance and we will try to reach out to you promptly. All the best in making kombucha.

  6. Sheena D October 19, 2016 at 9:57 pm - Reply

    Hello, When you add the store bought Kombucha, should it be room temperature?

    • Diane January 27, 2017 at 5:43 pm - Reply

      Sheena, The store bought kombucha can be resting at room temperature for about 10-20 minutes prior to adding it to the cooled tea. Make sure the cooled tea is below 90F / 32C before adding the live cultures in store bought kombucha. All the best!

  7. Sheena October 26, 2016 at 12:55 am - Reply

    I am happy to report that I successfully made my first SCOBY using store bought Kombucha. It took a while for the SCOBY to form. One minute nothing was there and then the next I had a fantastic SCOBY. I can’t wait to try it out.

    • Diane January 27, 2017 at 5:10 pm - Reply

      Sheena, This is fantastic news and thank you for your interest in our method. We hope you are continuing to have success with making delicious kombucha. All the best.

  8. Sandy October 30, 2017 at 3:55 pm - Reply

    Hi my first batch if Kambucha was delicious . Made a second batch but scoby is laying at the bottom of the brew. Is it dead?

    • Diane November 6, 2017 at 3:34 pm - Reply

      Thank you for your question. There are many reasons why a scoby may sit sideways in the jar, float or even sink. Generally all of these are normal and do not affect your brewing process. All the best in your Kombucha making.

  9. Dianne January 31, 2018 at 12:01 am - Reply

    Why is it recommended to not use a flavored black tea? For example, am earl grey?

    • Diane February 2, 2018 at 2:33 pm - Reply

      Dianne, Thank you for this question. We recommend using all black tea for growing the SCOBY, because black tea will produce the fastest cellulose growth. Other teas will work for growing the SCOBY but the growth will be slower and the SCOBY may be different (e.g., green tea SCOBYS tend to be thinner but are perfectly healthy). Once the first SCOBY is formed and the culture is up and running, any unflavored white, green, oolong or black teas will work beautifully.

    • Jessica Sipos March 14, 2018 at 7:12 pm - Reply

      I’ve heard there are oils in some teas, like Earl Grey, that can damage the scoby

  10. Tracy Stakelbeck March 31, 2018 at 5:54 pm - Reply

    Is there a way to make your own scoby without using anyone else’s live culture? Can you create your own live culture just as you do when making a sourdough bread starter? Catching bacteria and yeast from the air?

    • Diane April 2, 2018 at 4:14 pm - Reply

      Tracy, There may be a way to make your own starter scoby without using anyone else’s live culture starter but we do not have instructions to do that. We have never tried to catch bacteria and then start a scoby. Catching yeast for a sourdough culture is something we have done many times. Good luck in your efforts. If you are successful making a scoby starter, we would be interested to learn your method. All the best to you!

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