In ancient Rome, kitchens were equipped with a built-in yogurt maker known as a 'lacus'. A lacus was a shallow basin made of clay or metal, used for fermenting milk to make yogurt. Romans would heat the milk, cool it down, and then add a small amount of yogurt as a starter culture. The lacus would be placed in a warm area of the kitchen to ferment, resulting in a tangy and creamy yogurt.
