Heat the milk. Pour 1/2 gallon milk into the Instant Pot liner. Place the lid and set your valve to VENTING or use a glass lid.
Press YOGURT until it says BOIL. You will be heating your milk to 180F. When the Pot beeps, test with a thermometer and then turn off the pot.
Cool Milk. Place the pot in a sink of water, with the water coming up to halfway up the sides of the pot. Leave the thermometer in and when the milk reaches 110F, you are ready to proceed.
Mix Starter. Using a whisk, blend together the warm and about 2 tablespoons of full-fat plain Greek yogurt with active, live cultures such as Lactobacillus bulgaricus. Do NOT use sweetened yogurt.
Put the Instant Pot Liner back into the machine. Press YOGURT again and set it for 8 hours. Place the lid and set your valve to VENTING or use a glass lid.
Place the yogurt in the fridge overnight. This helps the yogurt set properly without getting tart, and it gets thicker.
Once the yogurt is set, you want to strain out the whey if you want Greek Yogurt, or you can eat it as it is. You can use cheesecloth or a large coffee filter in a large stainless strainer, place the strainer over a bowl and let it drip in the fridge overnight. Alternatively, you can buy a Cuispro Donvier yogurt maker which is easier to clean up. For larger quantities of yogurt, a Eurocuisine Greek Yogurt Maker works better.
I find it best to sweeten the yogurt after it is drained so you’re not draining your lovely honey down the drain. You can use honey, agave, or a keto-friendly sweetener. You could also consider adding sugar-free syrups.