Heat the milk in a saucepan until it reaches the 180 degrees. Allow it to cool back down to 70 degrees. Remove skin if you want or leave it, I leave it. Pour milk in yogurt maker then add in the yogurt. Whisk the two together until well combined. Set the maker to 24 hours. Once it has fermented for 24 hours, allow to cool for 6 hours. Will keep for 1-2 weeks