Critters in Your Kombucha?

Written by Barry Lee on
Critters in Your Kombucha
Source: Kombucha Kamp

Most kombucha drinkers know how it’s made: sweetened tea is fermented with a gelatinous blob called a SCOBY — a Symbiotic Colony OBacteria and Yeast. But just what kind of “symbiotic” life reside within? It varies from batch to batch. In fact, there are so many different microorganisms in kombucha that scientists have discovered entirely new species while studying SCOBYs! That might sound scary, but these critters are (mostly) harmless.


Most bacteria you’ll find in kombucha are part of a large group called acetic acid bacteria. As their name suggests, these bacteria produce acetic acid, which is what gives kombucha its slightly vinegary taste.

Lactobacilli are the second most common group of bacteria you’ll find in a SCOBY. Members of this genus are also used to make yogurt and are the major component of many probiotics.


Almost all fermented foods and beverages use some type of yeast, a group of microscopic single-celled fungi. In addition to the yeasts also used in baking and brewing beer, SCOBYs are home to a large number of more exotic species — including a few that haven’t been found anywhere else!

Mold is a more visible type of fungus that ideally shouldn’t be in a SCOBY but often is. Some of these molds can make you sick, so moldy kombucha cultures should be thrown out!


Unlike yeast and bacteria, worms are not a normal part of a healthy SCOBY. However, their presence is pretty common.

Vinegar “eels” are one type of worm that often finds its way into kombucha cultures. These nearly microscopic nematodes are resistant to acidic conditions and feed on bacteria and yeast. While unappetizing, it’s totally safe to drink kombucha that is infested with vinegar eels. Just keep in mind that these critters can destroy a SCOBY over time.

Other worms you may find wriggling around in homebrewed kombucha are fruit fly maggots. These are usually safe to swallow but definitely gross. Always make sure your kombucha is covered up to keep flies out!