Homemade Yogurt - With or Without the Instant Pot

Steps

1. In a large saucepan, heat milk slowly over low heat to 180 F, or until it is steaming and at a bare simmer with bubbles around the edges, but not boiling. Stir the milk occasionally as it heats. Remove milk from heat and cool milk down to 110 F or lower. It should be warm, but not hot. If you stick your finger in the milk for 10 seconds, it should feel pleasantly warm, but not hot. 
2. Transfer 1/2 cup of the warm milk into a small bowl and whisk in yogurt until it is well combined. Add this yogurt milk mixture back to the rest of the milk and whisk to make sure it is well combined. 
3. Place milk and yogurt mixture into a yogurt maker (see notes below) and set the time for 8-24 hours, until it is thick and tangy.
4. Transfer the pot to the refrigerator and chill for at least another 4 hours. It will continue to thicken as it chills.