Today, yogurt is one of the most universal and diverse foods in the world. People from the Mediterranean to South Asia make variations using distinct regional bacteria and milks—goat, sheep, cow, camel, yak. In the Middle East, yogurt is dehydrated in the sun, often with the addition of wheat, and turned into dense pellets or powders known as kashk that can travel well in hot, dry climates and keep through long winters. Rehydrated with water, it can thicken soups or serve as a garnish to cold weather stews. In India, yogurt makers hang the curds in muslin, draining the whey to produce a dense, luxurious cream (I like it best beaten with sugar and infused with cardamom in the dessert known as shrikhand). Other kinds of fermented milks have developed too—not technically yogurts but variations on the theme—like Icelandic skyr and creamlike viili from Finland, which is made with cultures that grow at cooler temperatures, producing milder flavors. In Russia and central Asia, yeast is added to the culture to make kefir and kumys, which produce alcohol as they ferment into wonderfully sour, fizzy drinks.