Pour 1/2 the milk into the Instapot with the active bacterial cultured yogurt. Whisk until well combined
Pour the vanilla and remaining milk into the pot and mix well. Place the lid on the pot and hit the yogurt button for 9 hours.
Open the Instapot and allow the pot to get to room temperature. Add your stevia if you want to sweeten it and gently add the probiotic capsules, cover with the pot with a tea towel and place in the fridge to chill.
After an hour check your yogurt and it should be ready to stir with a wooden spoon. Transfer it to a large glass container with a lid.
Yogurt will keep well for 1-2 weeks in an air-tight container in the fridge.