Homemade Greek Vanilla Yogurt in the Instant Pot

-1 gallon of milk
-2 Tbsp vanilla
-1/2 c. sugar
-1/4-1/2 c. yogurt for a starter
NOTE: Start in the morning. This takes very little hands-on time, but it takes 8 hours to incubate.
1. Pour the gallon of milk into the Instant Pot. Add vanilla and sugar. Stir until dissolved. DO NOT ADD YOGURT YET. Boiling will kill the active cultures.
2. Turn on Instant Pot. Press "Yogurt" and adjust until it says "boil". Wait for it to boil (about one hour).
3. Remove Instant Pot insert and place it in a cold water bath to reduce temperature to 110 degrees fahrenheit. Set a timer for 7 minutes. I always set a timer because if you forget it and the temp gets too low you have to heat it back up!
4. When the milk, sugar, and vanilla have lowered to 110 degrees, take it out of the cold water bath and dry off the outside of the insert. Place the insert with the milk mixture back in the Instant Pot.
5. Add yogurt to the milk mixture. Stir.
6. Turn on Instant Pot. Press "yogurt". Adjust until it says "8:00". This means it will now incubate for 8 hours.
7. After 8 hours the yogurt is done and ready to strain.
8. Set a tea towel or cheese cloth on top of a strainer. Put the strainer on top of a bowl to catch the whey. Pour yogurt into a tea towel/cheese cloth. Wait for it to strain. I start with 16 cups of milk and usually strain off 6 cups of whey. So I end with 10 cups of Greek yogurt.