In a small bowl or a glass measuring cup
, add the 1/4 cup water, 1 cup milk, and 3 tablespoons of butter. Microwave for about 30-60 seconds, checking to stir at least once, until it is lukewarm but not hot. You want the mixture to be about 105 degrees F. It's okay if the butter has not melted. If the mixture becomes too hot to comfortably stick your finger in it, put it in the fridge for a few minutes.