Like most people, when we hear the word "fermentation," our minds immediately jump to kimchi, kombucha, and sauerkraut. Fermentation isn't a process exclusive to food, though — it's a major component in certain skin-care products. In fact, fermentation has long been integral to the Korean and Eastern beauty market. And beer, apple cider vinegar, and yogurt have been used for centuries as at-home treatments. But as the technology and demand for fermented ingredients develops (and as marketers catch on to the trend), you can expect to see it just about everywhere.

Before you reach for that extra serving of kimchi, though, let's back up a bit. What the hell is fermentation, anyway? And what does it mean for your night cream? According to Craig Kraffert, MD, board-certified dermatologist and president of Amarte, fermentation is the metabolic process of converting sugars into acids, gases, or alcohols using yeast and/or bacteria. It's commonly used to make popular foods and drinks, but where skin care is concerned, fermentation holds a host of possibilities.

The most important: increasing the potency of ingredients like tea, ginseng, and rice. "Fermentation helps enhance the beneficial properties [of] natural extracts," says Dr. Kraffert. "It also causes the breakdown of larger organic plant structures and complex molecules into smaller — and potentially more bioactive — molecules." Translation: Because the molecules are smaller, they are more readily absorbed into your skin.

Mary Schook, licensed aesthetician and founder of M.S. Apothecary, adds that since most fermented ingredients are acidic, "They help to naturally exfoliate dead cells, allowing product to penetrate deeper." According to both Dr. Kraffert and Schook, fermented ingredients are often loaded with antioxidants and anti-inflammatory ingredients and can provide a calming and brightening effect to the skin. Schook also notes that many fermented ingredients are known for promoting healthy bacteria growth on the skin, while simultaneously eliminating bad bacteria.

But as we're sure your mother has told you a hundred times, everything in moderation. Schook warns that there are risks when using fermented products: "Because most fermented ingredients in skin care are acids, you have to worry about sun sensitivity," she says. So, be sure to diligently apply your SPF (which we know you always do anyway).

So grab a beer (or maybe a glass of kombucha) and check out our favorite fermented beauty products in the slides ahead.