So, what is fermentation? Fermented skincare, much like fermented foods, means that microorganisms (bacteria) have been added, which release enzymes that break down the ingredients. Your skin cannot easily absorb the actives in natural ingredients because of its molecular size, but by breaking down the molecules into smaller sizes, your skin can better absorb the skin-benefitting ingredients. “Just like fine wine, fermentation uses yeast in a natural chemical process to secrete enzymes,” says Caroline Chang, MD, a board-certified dermatologist at The Rhode Island Dermatology Institute. “The natural process of fermentation creates a higher concentration of beneficial ingredients like probiotics, vitamins, and antioxidants, and allows these key natural ingredients to be more potent. This not only helps fight free radical damage and protect against UV damage, it can also help produce amino acids, which are the building blocks of peptides to combat fine lines and wrinkles. Don’t worry—I’m not about to ask you to smear kimchi on your face (although we’ve done weirder things for the sake of beauty). Fermented beauty products just refers to the transformation process, and in fact, you might already be using it in your skincare routine. Take lactic acid, for example, which is derived from fermented milk. The commonly used anti-aging ingredient is now being joined by a new wave of products that are developed by fermenting all sorts of superfoods—mushrooms, green tea, wasabi, and more—to reap the benefits of this process. Below, some of my favorite fermented beauty products (which I’ll be applying alongside a large serving of kimchi and wine, naturally).