Pour milk into the Instant Pot inner pot
Press the Yogurt button, then select Boil
Heat the milk to 180°F
Remove the inner pot and let the milk cool to 110°F–115°F
Mix a small amount of plain yogurt with live active cultures into a little cooled milk
Stir the yogurt mixture back into the pot
Return the inner pot to the Instant Pot
Press the Yogurt button and set the incubation time to 8–12 hours
Let the yogurt ferment without disturbing it
Check for thickness and tanginess when the time is done
Refrigerate the yogurt for at least 4 hours
Stir before serving
Save a few tablespoons as starter for the next batch