Pour milk into instant pot, then press the yogurt button and adjust to boil.

After the pot beeps, make sure it has reached 180F. Remove the inside pot and allow milk to cool until temperature reaches between 105F to 115F. Remove the milk "skin" that forms on the surface.

Whisk in yogurt, then return inner pot to the instant pot. Press the yogurt button again and set for 8 hours. The sealing valve does not have to be closed.

After completion, add vanilla extract and whisk the yogurt again. If it seems too runny, drain yogurt with a cheesecloth and strainer.