Homemade Kombucha Fermentation: How To

Kombucha, the fizzy fermented tea beverage packed with probiotics, has gained tremendous popularity for its potential health benefits and refreshing taste. While store-bought versions can be expensive, brewing kombucha at home is surprisingly simple and cost-effective. With just a few ingredients and some patience, you can create your own customized kombucha flavors right in your kitchen.

What You’ll Need

The foundation of kombucha brewing starts with a SCOBY (Symbiotic Culture of Bacteria and Yeast), which looks like a rubbery pancake and contains the living organisms necessary for fermentation. You can obtain a SCOBY from a friend who brews kombucha, purchase one online, or grow your own from store-bought raw kombucha.

Your essential ingredients include black or green tea bags, white sugar, filtered water, and starter tea from a previous batch or store-bought raw kombucha. Equipment-wise, you’ll need a glass jar, coffee filters or cloth, rubber bands, and bottles for the final product. Avoid metal containers during fermentation, as they can damage the SCOBY.

The First Fermentation Process

Begin by brewing a strong tea concentrate using eight tea bags in four cups of boiling water. Steep for 10-15 minutes, then remove the bags and stir in one cup of white sugar until completely dissolved. The sugar feeds the SCOBY during fermentation, so don’t reduce the amount or substitute with artificial sweeteners.

Allow the sweet tea to cool to room temperature—hot liquid will kill your SCOBY. Once cooled, pour the mixture into your glass jar and add two cups of starter tea. This acidic starter creates the proper pH environment for safe fermentation and prevents harmful bacteria from taking hold.

Gently place your SCOBY into the mixture with clean hands. The SCOBY may float, sink, or sit sideways—all positions are normal. Cover the jar opening with a coffee filter or breathable cloth secured with a rubber band. This allows the kombucha to breathe while keeping dust and insects out.

Place your jar in a warm, dark location away from direct sunlight, ideally between 75-85°F. Fermentation typically takes 7-14 days, depending on temperature and taste preferences. Warmer conditions speed up fermentation, while cooler temperatures slow it down.

Testing and Tasting

After seven days, begin tasting your kombucha daily using a clean spoon. The flavor should gradually shift from sweet to tart as the SCOBY consumes the sugar and produces beneficial acids. When it reaches your desired balance of sweetness and tanginess, the first fermentation is complete.

During this process, you’ll notice a new SCOBY layer forming on the surface—this is completely normal and indicates healthy fermentation. The liquid may also develop small brown stringy bits, which are harmless yeast strands.

Second Fermentation for Flavor and Fizz

Reserve two cups of your finished kombucha as starter tea for your next batch, then transfer the remaining liquid to bottles, leaving about an inch of headspace. This second fermentation stage allows you to add flavors and develop carbonation.

Popular flavoring options include fresh fruit, fruit juices, herbs, or spices. Try combinations like ginger-lemon, berry blend, or mint-cucumber. Add your chosen flavors directly to the bottles, then seal tightly and leave at room temperature for 2-4 days.

The sealed environment during second fermentation creates natural carbonation as the remaining sugars ferment. Check bottles daily by opening slightly to release pressure and test fizz levels. Once you achieve your preferred carbonation, refrigerate to slow fermentation.

Safety and Storage

Properly fermented kombucha should smell pleasantly tart and yeasty, never foul or rotten. If you notice fuzzy mold growth on your SCOBY (usually green, black, or blue), discard everything and start fresh. Healthy kombucha is acidic enough to prevent harmful bacterial growth.

Store finished kombucha in the refrigerator for up to several months. The flavor will continue developing slowly, becoming more vinegary over time. With practice, you’ll master the timing to achieve your perfect balance of flavor, fizz, and probiotic benefits in every batch.