If you’ve made kombucha or bought unfiltered kombucha from a store, you’ll likely notice a build-up of sediment at the bottom. It usually looks brown, may be cloudy, or even slimy. Although it may look sketchy, it’s quite normal. Kombucha is a sweet tea that is fermented with a kombucha culture commonly referred to as the SCOBY. The word S.C.O.B.Y. is an acronym, which stands for “symbiotic culture of bacteria and yeast.” If you would like to learn more, the post here covers in detail, “What’s a SCOBY?”.
The build-up you see at the bottom of your kombucha is simply an array of yeast and bacteria cells that have settled to the bottom of your bottle or brewing vessel. If you are here because of dark spots at the surface or brown stuff suspended in your liquid, see our post which covers the brown stuff floating in kombucha. If you’re interested in learning more about the kombucha brewing process, check out our article on how kombucha is made.
During the kombucha fermentation, the yeast in the kombucha culture consumes the sugar suspended in the liquid and converts it to ethanol and carbon dioxide. The bacteria then convert that ethanol to various acids, which is what makes kombucha tart. As fermentation progresses and after it’s bottled, some of the yeast and bacteria suspended in the kombucha will begin to settle at the bottom. This is why the sediment is seen at the bottom of both fermenters and bottled kombucha. As the fermenter or bottles sit, yeast and bacteria fall to the bottom. This is sediment you see – a mixture of this yeast and bacteria.
Absolutely. The yeast and bacteria in kombucha are not only safe to drink; they’re good for you! You’ve likely read or heard about the health benefits of drinking kombucha. The benefits are attributed to the fermentation – the yeast, bacteria, and their by-products. Kombucha is similar to other fermented foods including sauerkraut, sourdough bread, kimchi, and apple cider vinegar, in the sense that all of these foods contain varying amounts of healthy probiotics. So, of course, these are safe to consume, and kombucha is safe to drink. To learn more, see our post on the health benefits of kombucha tea.
The build-up of yeast and bacteria in kombucha is unavoidable unless it is filtered. So unless you are filtering your batches or buying filtered bottled kombucha, the sediment will always be there in some capacity.
So, while odd-looking at first, the residue at the bottom of your kombucha is entirely normal. If you don’t like the idea of drinking the sediment, you can filter it out or pour it slowly from your bottle, leaving the sediment behind. There will still be beneficial bacteria and yeast in the rest of your drink.
