Optional Equipment Sterilization: Place 2 cups of cold water and a trivet in the Instant Pot. Place silicone spatula, Pyrex glass measuring cup, and tablespoon measuring spoon in the Instant Pot. Close the lid and move the Venting Knob to Sealing Position. Sterilize everything at High Pressure (Use the manual/pressure cook button) for 3 minutes + natural release. Or Sterilize on Stovetop: sterilize the equipment (including meat thermometer) on stovetop by boiling them for 10 minutes.
After sterilization, air dry the equipment on a clean rack.
Heat Milk to 180°F - 200°F to Denature the Protein: Pour 2L (½ gallon) of whole milk in the inner pot. Close lid (venting knob position doesn’t matter). Use the Yogurt More function to boil the milk to at least 180°F. It will say “boil” on the screen. It will take roughly 35 minutes – 40 minutes. The Instant Pot screen will change to “yogt” when the boiling is done.
Check Milk Temperature: Open the lid. Check the milk temperature immediately in a few spots and make sure the milk is over 180°F. Stir with a silicone spatula and check the temperature again to make sure the milk is over 180°F.
*Pro Tip: If the milk is not over 180°F, close the lid and heat the milk with the Slow Cook Less function for another 15 minutes.
Prepare Yogurt Starter: After the milk is heated over 180°F, place 32g (a little more than 2 tbsp) Dannon/Danone 4% Plain Greek Yogurt with Active Bacterial Cultures into the Pyrex glass measuring cup. Do not add the yogurt starter to the hot milk, as it will kill the bacterial cultures. (If you sterilized the measuring cup, make sure it has cooled to the touch). Cool Milk to 111°F: You can leave the pot on counter-top and wait until the milk cool to 111°F. Or alternative method to quickly cool down the milk temperature: Fill a larger pot or kitchen sink with cold tap water. Partially submerge the inner pot with heated milk into the cold tap water. Stir the milk in a circular motion with a silicone spatula and frequently measure the temperature. It will take 2 minutes – 4 minutes to cool the milk to 111°F. Remove the pot from cold water immediately. *Pro Tip: Try not to touch the bottom of the pot with the spatula as it may have some milk solid stuck to the bottom of the pot.
Add Yogurt Starter: Add ½ cup of 111°F milk to the Pyrex glass filled with yogurt starter. Gently mix it with the tablespoon measuring spoon. Pour the yogurt milk mixture in the inner pot and give it a few gentle stirs with silicone spatula.
Yogurt Incubation: Place inner pot back in the Instant Pot. Close lid (Venting Knob position doesn’t matter) and use the Yogurt Normal Function to incubate the yogurt. Adjust the time to 8:00 hours – 12:00 hours depending on how tangy you like your yogurt (longer time = more tangy). You can open the lid for a taste test once the yogurt is set. Roughly 6 hours. *Pro Tip: Don’t disrupt the fermentation process by moving the Instant Pot or opening the lid. Wait until it is set (roughly 6 hours) before opening the lid.
Strain Yogurt & Stop Incubating Process: Once the yogurt has reached the desired tangy level, pour the yogurt into a Greek Yogurt Maker to separate the whey from the yogurt. Place the Greek Yogurt Maker into the fridge to stop the incubating process. Greek yogurt will be ready to serve in 3 hours – overnight depending on how thick you like it.
*Pro Tip: If you think the Greek Yogurt is too thick, you can stir some of the whey back in with a whisk to adjust the thickness.
Serve: Plain Greek Yogurt is done. Serve by adding sweeteners such as honey or maple syrup. Add fruits, granola or your favorite toppings.