How to Make Kombucha at Home

Effervescent, bursting with sweet-tart flavor, fermented, and wildly popular, kombucha has been around for more than two thousand years. It has become more in-demand in the last few years; Kombucha Brewers International, a trade organization of kombucha brewers, estimates yearly sales of this fermented tea at over $500 million as consumers seek out a drink option that is low in sugar compared to soda and also boasts probiotic benefits.

The health angle is part of its appeal; kombucha is full of live and active cultures, similar to yogurt or sour pickles. It also includes B vitamins, organic acids, and antioxidants, says Hannah Crum, co-author of The Big Book of Kombucha: Brewing, Flavoring, and Enjoying the Health Benefits of Fermented Tea. But while you can buy bottles of this refreshingly fizzy, slightly sour beverage at most grocery stores, you can brew kombucha at home for just pennies a glass. If creating a microbiology project in a warm, dark closet sounds like a good time, welcome to the world of home-brewing fermented beverages.

It's easy to get this brewing project started. Kombucha is one of the simplest homemade drinks to make. From start to finish, brewing and fermenting kombucha only takes seven to 10 days. And you probably have many of the tools you need to start your first batch of homebrew already. "It's easy to do; the only elements you need are tea, sugar, a jar for fermentation and some starter or culture," says Zane Adams, founder and Co-Chief Executive Officer of Buchi Kombucha in Asheville, North Carolina, of brewing kombucha at home. Here's how to get started:

Step 1: Make the Tea

Crum notes that just as you would select the finest seeds to start your garden to ensure a bountiful and flavorful harvest, you should select the finest tea leaves possible to brew kombucha; preferably black, oolong, or green tea. Adams recommends keeping the brew small so it is easy to manage. Bring 3 quarts of water to boil in a pot or kettle. Filtering the water before you boil gives an extra layer of protection against unwanted bacteria. Add tea leaves or tea bags (the strength of the brew is a matter of personal preference). Add ½ cup sugar or honey and let it dissolve in the tea as it cools to room temperature.

Step 2: Start Fermentation

Kombucha transforms from tea into a fermented beverage when you add a starter culture to the mix. "Just as wine is fermented grapes and sauerkraut is fermented cabbage, we use a starter culture called a SCOBY that is added to sweetened tea," Crum explains. "SCOBY" is an acronym for "symbiotic culture of bacteria and yeast." It's a close cousin to the "mother" used to make vinegar. You can source a SCOBY from a friend, or order one online (and after you brew your first batch of kombucha, you'll have a SCOBY to use for future batches). A SCOBY looks like a flat, pale, floating mushroom, and its texture is rubbery and a little squishy. To use it, simply gently slide the SCOBY into the jar of tea with clean hands. It will spread across the surface of the kombucha during fermentation, so its bacteria and yeast can eat most of the sugar in the tea during the fermentation process.

You can ferment your kombucha with starter tea instead of a SCOBY. Starter tea is tea from a previous batch of kombucha or store-bought, unpasteurized, neutral-flavored kombucha. Pour 12 ounces of starter tea and the cooled sweetened tea solution into a wide-mouth 1-gallon glass jar.

"Avoid brewing in copper pots or jars and keep a tight weave tea towel well affixed to the top of the jar to prevent flies," says Adams. Cloth, coffee filters, or paper towels secured with a rubber band allow for air flow while keeping out unwanted pests and debris.

Step 3: Let It Brew

Store the jar of kombucha at room temperature, ideally between 75°F-80°F, out of direct sunlight, and in a place where it won't get jostled. Ferment it for seven to 10 days—just ignore it. Crum suggests avoiding looking at the brew until at least seven days have passed. The SCOBY can look strange, like a science experiment complete with tentacles hanging down and floating in the murky liquid. This is normal, as the yeasts hover near the surface at the beginning of the brewing process until the bacterial cellulose fills in the surface. "This can lead some people to think they have mold or something is wrong with the brew," Crum notes.

Step 4: Bottle Your Kombucha

After you brew your first batch of kombucha, you'll have a SCOBY to use for future batches.

Remove and save the SCOBY, then measure out 12 ounces of starter tea from this batch of kombucha to help start the next batch. Pour the fermented kombucha (straining it, if you prefer) into bottles or jars. Leave about a half-inch of headroom in each bottle for the carbon dioxide that may build up in the bottle, and store your bottles in a cool area (50°F-70°F), to slow the fermentation process and prevent explosions for 24-36 hours. This is when you can add juice, herbs, or other botanicals to your kombucha as additional flavoring. Use small amounts of dried or fresh flowers, bark, whole spices, and fresh herbs to infuse flavor without risking blowups; chamomile, ginger, turmeric, and apple slices are nice additions to your brew. Let them infuse for at least 2 hours, then enjoy your homemade kombucha.