There are so many ways to learn and play with kombucha including brewing, flavorings, and recipes but why let all the adults have the fun? Get your kids involved in the process and they won’t even know that they are learning a little about science.


If you are new to kombucha, check out this link to learn the basics. In this post we will explore a second fermentation experiment with the effects of carbonation using a balloon.


After you have brewed your batch and have waited 7-30 days for the SCOBY to eat the sugar in your sweet tea of choice, you are ready for the second fermentation process and our simple experiment! To clarify, the process of allowing kombucha (or other cultured foods) to undergo fermentation for a second period of time is without the starter culture present. When the kombucha is moved to a new container for bottling this is considered the second fermentation period. This fermentation is generally undergone in an airtight environment to encourage carbonation.


After you have completed the first fermentation period, leave the kombucha unflavored or add your kombucha fruit, fruit juice or extract in proper proportions to your bottles. Here comes the fun: instead of bottling the kombucha in an airtight container, place a balloon over the top of the bottle and leave in at room temperature for 2-14 days. The length of time you allow your kombucha to ferment for a second time depends on your personal taste preferences, the temperature of your fermentation area, and the types of flavors you've added. No matter what the conditions are, it's best to check on it frequently to avoid a mess.

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You can play with the different lengths of times for the second fermentation. For example, place three balloons on 3 different bottles: each one fermenting longer than the other. See how the balloon inflates with the carbonation. Just be sure you keep an eye on it so the balloons do not burst.


Please note that even though there is not a SCOBY present during second fermentation, the finished kombucha still contains live cultures that will continue to ferment and release carbon dioxide. If left long enough, however, a kombucha SCOBY or yeast strands may form spontaneously in a bottle of undergoing a second fermentation. This is normal and safe to consume.


Here is a photo of on of our employees' daughters having fun with this kombucha experiment. She wouldn't believe us that the balloons would inflate so she was very surprised!

About the Author: Cultures for Health Team

At Cultures for Health we believe that anyone--on any diet and at any skill level--can make and enjoy the benefits of traditional fermented foods. We hope these stories from our cultured kitchens will inspire you to nourish your family and live healthily. Happy Culturing!