Culinary Arts

What Is Kombucha? Learn How Kombucha Is Made and Why Kombucha Is so Popular

Written by MasterClass

Aug 13, 2019 • 2 min read

Kombucha has made its way out of the health food store and into the mainstream.


What Is Kombucha?

Kombucha is a fermented tea beverage that likely originated in China, spreading both through Russia to Eastern Europe and to Japan and Korea at least a few hundred years ago.

Why Has Kombucha Become so Popular?

Renewed interest in wellness, especially our gut bacteria, has made kombucha a multimillion-dollar business. Once made predominantly by home brewers, the effervescent drink is now sold widely in supermarkets. Kombucha also naturally contains some alcohol, though how much depends on how it’s made.

Commercial kombucha contains less than 0.5% alcohol by volume, since kombucha with higher alcohol content must be regulated by the Alcohol and Tobacco Tax and Trade Bureau (sometimes marketed as “hard” kombucha).

What Are the Health Benefits of Kombucha?

Like other fermented foods such as kefir and sauerkraut, kombucha is probiotic, which means that it contains beneficial bacteria. Kombucha also contains B vitamins, vitamin C, acetic acid, and lactic acid.

What Is a SCOBY?

SCOBY stands for “symbiotic community of bacteria and yeasts.”

Like a vinegar “mother,” sourdough starter, or ginger bug, a kombucha SCOBY is the microbial community that kick-starts the fermentation process. It’s also known as a “tea fungus” or “tea mushroom,” though the SCOBY is not actually a mushroom—it’s a gelatinous mass that contains the yeasts and bacteria that turn sugary tea into kombucha.

  • The exact bacteria and yeast living in a SCOBY will vary, but often include Saccharomyces cerevisiae and Gluconacetobacter xylinus.
  • You can make a SCOBY by pouring some kombucha in a wide-mouth jar secured with cloth. Wait about a week for a film to form. This is the SCOBY, and it will grow as you make your own kombucha, forming a new layer on top of the old. If you know someone who brews their own kombucha, you can ask them to give you a piece of their SCOBY.
Kombucha in jars with cloth covering


How Is Kombucha Produced?

Homemade kombucha is made by steeping tea leaves (usually black tea, but kombucha can also be made with other teas from the Camellia sinensis plant, such as green tea, white tea, or oolong tea) in hot water with sugar.

  • When the tea is strong enough, the leaves are removed and some kombucha from a previous batch is added to the sweet tea broth, increasing the acidity of the fermentation environment and preventing the growth of unwanted microbes.
  • The mix is transferred to a fermentation vessel, such as a wide-mouth glass jar, and a SCOBY is added to introduce the desired microbes.
  • The mixture is covered with a cloth, coffee filter, or other material that allows the exchange of gases but prevents the entry of bugs.
  • The kombucha is then left to ferment at room temperature until it reaches the desired flavor, alcohol content, and fizz. During the fermentation process, yeast produces alcohol, which bacteria converts into acid.
  • A new layer of SCOBY forms on top of the old one, and the kombucha will become lighter in color, produce bubbles, and taste vinegary.
  • After the initial fermentation, the SCOBY is removed and stored with a small amount of kombucha.
  • The kombucha can then be strained and bottled, or can continue to ferment for another few days on the counter, or at a slower rate in the fridge. Once fermentation is complete, some brewers add flavorings such as herbs or fruit.

Become a better chef with the MasterClass All-Access Pass. Gain access to exclusive video lessons taught by culinary masters, including Chef Thomas Keller, Alice Waters, Gordon Ramsay, and more.