Fermented foods — like yogurt, wine, and kimchi — are everywhere, and may even contain probiotics that help with gut health. Fermented ingredients just may work wonders on your skin, too, and are increasingly popping up in moisturizers, toners, and serums.

But how exactly does fermentation benefit your skin? We asked skin-care experts to break down the hows and whys of a traditional K-beauty approach that is now gaining traction stateside. 

Meet the experts:

What is fermented skin care?

“Usually, you think of fermentation when it comes to wine [or] kimchi, but it can also be applied to skin care,” says Shereene Idriss, MD, a New York City-based board-certified dermatologist. And just like cabbage is fermented in salt to make kimchi and grapes are fermented in yeast to make wine, fermentation in a lab harnesses microorganisms, such as bacteria, to break down skin-care ingredients into different compounds.

Fermented skin-care ingredients come from nature, but not all of them are plants. Cosmetic chemist Ginger King keeps fermented mushrooms in her lab, and says they have antioxidant, anti-inflammatory, and anti-bacterial properties. She also keeps fermented ginseng root on hand and fermented rice extract, as both can help smooth wrinkles, she says.

How does fermentation benefit skin?

Fermentation is science’s way of sticking a ray gun to ingredients and making them smaller, Honey I Shrunk The Kids-style … and it is worth it because there is the potential for those broken-down ingredients to penetrate your skin. “Active ingredients that have been fermented with yeast or bacteria break down to smaller molecules for better absorption,” explains King.

But it’s not just that fermented skin-care ingredients can potentially absorb better than their counterparts. Based on some studies (more on those later), these products might work better, according to Marisa Garshick, MD, a New York City-based board-certified dermatologist. “[Fermenting skin care] increases the potency of the ingredients,” she says. “Additionally, fermentation can be helpful for the skin microbiome as fermentation can result in probiotics or postbiotics in the form of peptides, acids, and enzymes, which can help to support the skin barrier and as a result reduce the potential for skin inflammation and sensitivity.”