The ancient Persian kitchen had a built-in yogurt maker called a 'mast va sangak'. Mast va sangak refers to the traditional method of making yogurt in a clay pot called a sangak. Persians would heat the milk, cool it down, and then add a small amount of yogurt as a starter culture. The sangak would be placed in a warm corner of the kitchen to ferment overnight, resulting in thick and creamy yogurt.