Yoghurt (also spelled yogurt) is a thick, creamy food made by adding helpful bacteria to milk and letting it ferment. The bacteria eat the milk's sugar and transform the milk into something tangier and thicker, with a distinctive sour taste that many people love.

People have been making yoghurt for thousands of years, probably discovering it by accident when milk was stored in warm places. Today it's eaten plain, sweetened with honey or fruit, or used in cooking. Greek yoghurt is strained to make it extra thick. In Indian cooking, yoghurt appears in dishes like raita and lassi. Middle Eastern cuisines use it in sauces and marinades.

Yoghurt contains probiotics, which are beneficial bacteria that help your digestive system. It's also rich in protein and calcium. Many people eat it for breakfast with granola and berries, blend it into smoothies, or use it as a substitute for sour cream.