What is Kombucha, really? Here's what you should know

If youve ever found yourself wandering through the beverage coolers at a Whole Foods, dining at a trendy brunch place with your health-obsessed friend, or staring down your roommates unexplained but intentional growth of bacteria in the kitchen, youve probably been forced to ask: "What is kombucha?"

Let's start with the basics. Kombucha, which has been around for over 2,000 years, is a fermented drink made from bacteria and yeast mixed with black or green tea and sugar. The sugary tea turns into kombucha with the help of a SCOBY—a.k.a. "a symbiotic colony of bacteria and yeast"—which looks a bit like a floating mushroom. Except it's made of live bacteria. It's this bacteria and yeast-fueled fermentation process that sets kombucha apart from other drinks (and gives it that slightly off-putting vinegary smell when you sip).

Despite the off-putting origins of kombucha, the resulting bubbly drink offers plenty of health benefits, including improved digestion and immune function, says Lisa Moskovitz, R.D. Thanks to that fermentation process, kombucha is packed with probiotics as well as B vitamins, enzymes, and organic acids. It might also help you de-bloat —always a good thing!

Before you buy (you can find the stuff at health foods stores, most grocery stores, and even some coffee shops and bars these days), there are two main things you should know:

1. Don't drink too much. While a little kombucha is good, too much can cause issues like heartburn. "About four ounces of commercially-prepared kombucha is safe and can be effective," says Moskovitz. However, anyone who is pregnant or has a compromised immune system shouldn't drink it, she adds. Why? Since it's made with bacteria, there is always the risk of contamination that might make you sick. "Some versions can be unpasteurized, particularly home-brewed versions, which result in toxic reactions and can be harmful to a fetus," Moskovitz says. If you're otherwise healthy, you shouldn't worry too much about store-bought versions, but drinking a homemade brew can be riskier.

2. Avoid alcoholic versions. Fermentation, in case you don't remember from chem class, is also the process by which alcohol is made. So technically, all kombucha is a teeny bit alcoholic. Some versions of kombucha are actually allowed to ferment long enough to give you a bit of a buzz and "can contain as much alcohol as a light beer," says Moskovitz. Check the label before taking a swig and stick to the low-alcohol versions if you want to keep your kombucha as healthy as possible.

If you want to make your own (because yes, you can totally DIY it!) we recommend following this helpful step-by-step guide from our friends at Rodale's Organic Life. But be warned: Handling that SCOBY on your own can be a little gnarly.