Pour 1/2 gallon of milk into the Instant Pot. Put the lid on, it doesn’t matter where the valve is as this does not need to come to pressure.

Press the yogurt button until the display reads boil. The Instant Pot will begin to heat the milk, this takes up to an hour. It will beep when it is done. The temperature should read 180 degrees.

Once the Instant Pot beeps you need to let the milk cool. Take the inner pot out. You can let it cool on the counter for about an hour or in a large bowl of ice for about 20 minutes.

When the milk temperature is between 105-110 degrees remove the skin off the top. Whisk in 1/4 cup plain yogurt until smooth. Be careful not to scrape the bottom of the pot.

Place the lid back on the Instant Pot and press the yogurt button. The display will read yogurt and will have a time of 8 hours.

After 8 hours, check on your yogurt. If you can stick a spoon in it and it stands up without falling over, the yogurt is thick enough and is done. If you aren’t quite there yet press the yogurt button and adjust the time to cook another 1-2 hours until yogurt is thick.