Cool Milk to 110°F
110°F is the temperature at which the yogurt cultures will consume the lactose in the milk, and reproduce themselves. You could wait for the milk to cool on its own, but this is much faster and more efficient.
- Carefully place pot of milk in cold water bath
- Stir occasionally
- Like before, you want the level of cold water in the sink to be about even with the level of milk in the pot.