Place the milk in a saucepan and gently pre-heat to 100-110° F. Once the temperature is reached, remove from heat and whisk in 1 package of the yogurt starter. This spreads the good bacteria throughout the milk.
Place milk in yogurt jar or jars without lids and incubate in your yogurt maker for 6-8 hours at 110°F. If it's still not set, continue to let it ferment - up to 15 hours total or more until it sets. You'll know it's done when you see a thick curd. See note*
Place the jars in the fridge to cool and set. Cool the yogurt in the refrigerator for at least six hours. As the yogurt cools, it will get even thicker!