Yogurt has been a beauty ingredient far longer than it’s been a breakfast food — or at least, people figured out its skin benefits around the same time they figured out it tasted good. Ancient Egyptian and Indian women used fermented dairy on their skin as a matter of routine, not as a luxury. Cleopatra’s famous milk baths were likely closer to a fermented dairy soak than the fresh milk version the stories tend to romanticize. There’s something satisfying about an ingredient whose resume spans several thousand years.
In soap, yogurt contributes lactic acid — a gentle alpha hydroxy acid that helps skin look brighter and feel smoother over time — along with proteins and fats that add a silky, conditioning quality to the lather. The sugars in yogurt also boost bubbles in a really lovely way, giving bars a creamier, more luxurious feel than you’d expect. It’s the kind of ingredient that doesn’t announce itself but makes everything around it better.
Best Uses: Complexion bars, everyday facial soap, gentle exfoliating bars, and any formula aimed at a soft, creamy lather with a skin-smoothing effect.