Pour cold milk into cold/cool Pressure Cooker cooking pot.
Cover with lid, and lock into place.
Push the “Yogurt” button and adjust until it reads “boil”
During the boil cycle, remove lid and whisk milk from time to time with a wire whisk to help it heat evenly.
Once the beep sounds, open, whisk it once, then take the temperature with your instant read thermometer. If it is not at 180 degrees, turn it onto the Sauté/Low function to get it up to temp, whisking continuously, and keeping the instant read thermometer in there.
When 180 degrees is reached, remove cooking pot and put it in a sink of cold water.
You will want to whisk and take temperature readings often, as you try to get to 95-110 degrees.
If in a hurry, change out your water, as it will heat up from the pot.
Once you reach the 110 degree mark, scoop 1 cup of milk out of your liner and put it in a bowl, and whisk in 2-3 Tbs of your starter. This is a plain yogurt with active cultures such as Fage or Oui. Just check the package at the store.
After whisking the starter with the milk, dump all of it into your cooking pot, and whisk it together thoroughly.
If adding sweetener (sweetened condensed milk), this is the time to add it. Put it in, whisk it all together.
Place cooking pot/liner back into the Instant Pot and cover with IP Lid, lock it into place.
Press “Yogurt” button until display reads 8:00. Or 8:00 Normal. This is the incubation period.
Now walk away and let it incubate, do NOT stir it during this time.
When the time is up, remove cooking pot, cover with glass lid or plastic wrap, and place in your refrigerator to cool, 6-8 hours. Do not stir.
At this point you have yogurt, to make it Greek style, you will now use a yogurt strainer, and strain the yogurt in the refrigerator for at least 2 hours. The whey straining off should be clear, not cloudy. If cloudy, add another layer of cheesecloth. Or use the Euro Strainer, which is easy and great.