Rice Ferment Filtrate

Rice ferment filtrate is a traditional Japanese ingredient derived from fermenting rice with koji (Aspergillus oryzae), the same mold used to make sake, miso, and soy sauce. The fermentation process breaks down rice into amino acids, vitamins, enzymes, and other bioactive compounds that benefit the skin.

Also known as sake filtrate or sake kasu, this ingredient has been used in Japanese beauty rituals for centuries. Geishas would apply sake lees to their skin for brightening and moisturizing effects. Modern formulations concentrate these fermented extracts and combine them with other actives for enhanced efficacy.

Rice ferment filtrate gently exfoliates, brightens, hydrates, and provides antioxidant protection. It contains kojic acid (a natural byproduct of fermentation), amino acids, and organic acids that improve skin texture and tone. Brands like Kikusamasamune, Sake no Shizuku, and Tatcha have built their reputations on fermented rice ingredients.