Bring the milk to a boil and turn off immediately. Let cool to room temperature. 

With a wire whip, beat in 2 tablespoons of yogurt until completely blended. 

Pour the mixture into a clean pint-sized jar. If you have a yogurt thermos, use that. Otherwise, wrap the jar in two terry cloth dish towels. 

Place in an area that is not drafty over night. The next day the yogurt is ready. Refrigerate after opening.