Pour milk into Instant Pot cooking pot and cover with glass lid or black instant pot lid.
Push the Yogurt button and then step through the displays on the screen until it reads "Boil."
During the Boil cycle, remove the lid and whisk the milk a couple of times during the cycle.
When the beep sounds, remove the lid and measure the milk's temperature. Anywhere from 170 to 180 degrees Farenheit is fine.
Slowly pour in the lemon juice or vinegar and very gently stir the milk. You should start seeing signs of the milk curdling almost immediately. If you don't, add a tiny bit more lemon juice or white vinegar.
Turn off the Instant Pot. Cover the milk in the pot with the glass lid and let sit for at least 30 minutes.
If you are adding buttermilk or cream, measure it and set it in the fridge.
Pour the cottage cheese into a strainer lined with cheesecloth that you have placed inside a larger bowl or pot OR place it in the greek yogurt strainer.
Allow the whey to drain from the cheese. (This could take an hour or so)
If the cottage cheese still seems to have a lot of liquid after the whey has drained, place it in a colander lined with cheesecloth, gently gathering the cheesecloth around the cottage cheese in a bowl and gently squeeze to remove additional whey.
Once you are happy with the dryness of your cottage cheese, stir in the buttermilk or cream if you are using. I did not do this when I made my cottage cheese, but create your mixture according to your desired tastes.
Refrigerate and enjoy within 5 days.