Pour milk into inner pot of Instant Pot. Push yogurt button until the screen reads "boil." (Usually you will need to hit the yogurt button two times) This will take about an hour.
Once the Instant Pot beebs that the boil cycle is complete, carefully remove the lid and test the temperature. It should be around 180 degrees Fahrenheit. Let inner pot sit in instant pot for 5 minutes and then remove inner pot.
Allow the milk to cool to 105-115 degrees. This will take an hour on the counter top or about 15 minutes if you place your inner pot into an ice bath.
Gently skim off the "skin" on the yogurt and discard.
Whisk in the prepared yogurt.
Place inner pot (be sure to dry off well if you had in ice bath),put lid on and press yogurt button again and then adjust until screen reads 8:00. (The pressure should also read normal--if it reads less, hit adjust again until normal is lit up.)
Once yogurt beeps that it is complete, remove the inner pot from the inner pot and cover with plastic wrap. Refrigerate for 8 hours before transfering to individual containers.
This is a great time to freeze some yogurt for future yogurt making.
Instead of prepared yogurt as your starter, you can use a yogurt starter. Just follow directions to determine how much starter to add to 1/2 gallon milk (each brand is a bit different.)
You can use any percentage of fat to make homemade yogurt.
To make Greek yogurt, strain the yogurt in a strainer lined with cheesecloth overnight in the fridge (be sure to place over large mixing bowl while draining.)
Homemade yogurt should last for about 10-14 days.
If sweetening yogurt, I have found it is best to add in sweeteners/vanilla after the yogurt has set up in the fridge for at least 8 hours, or after straining.
If you find your milk is not reaching 180 degrees after the boil cycle, you can turn to saute function for a few minutes, watching VERY closely to help it reach to 180 degrees.
Nutritional values are approximate and have been calculated using 2% milk. The serving size is approximately 4 ounces.