In a clean Instant Pot insert, add 8 cups of whole milk and set the yogurt function to BOIL.
Once the timer is finished, test the temperature. You want it to read 185 degrees. If it is not warm enough, set it SAUTE function and simmer until it reaches the correct temperature.
Allow to cool to 110 degrees. You can either let it sit out or fill your sink base with ice and place the insert. This will cool the milk faster, about 10 minutes or so, so stand by! You will want it to be 110 and not lower. This helps the cultures to properly multiply and will help your yogurt to set up properly.
Once cooled, remove 1 cup of warm milk and stir in 2 tablespoons of yogurt culture. You can get this from grocery store yogurt (make sure it says contains live cultures) or from a previous batch. Pour back into the insert and gently whisk in until just combined.
Place the lid back on, make sure the vent is at the open position, and set the yogurt function to 10 hours. After 8 hours, you may gently insert a spoon to check the flavor and consistency. If it is thick enough for your preference, you are finished. If not or you want a little more of a tangy flavor, let cook the remaining 2 hours.
Once complete, remove the insert, cover with plastic wrap and place in the fridge overnight. In the morning, your Instant Pot yogurt is done. Separate into 4 pint sized Ball jars and then enjoy within 2 weeks.
