Cheesecloth (Optional): to strain the yogurt for Greek yogurt/thicker yogurt, if desired. You can buy cheesecloth at most grocery stores in the baking or kitchen gadget section.
1/4cupyogurt with active cultures (or yogurt starter)*
Before starting, clean your 6 or 8 Quart Instant Pot really well with soap and water, or sterilize it by adding 2 cups of cold water, closing the lid and sealing the vent, and setting it to high pressure for 3 minutes, with a natural release.
Heat milk to 180-200 degrees. Add milk to the instant pot and place the lid on it (it doesn’t matter if the vent is sealed or not). Press the “yogurt” button and then press “adjust” until the screen says “BOIL”.
When the Instant Pot beeps, the milk is hot and ready. Remove the lid and check the temperature with a thermometer to make sure it has reached 180-200 degreed F.
Allow milk to cool to down to 110°F -115°F degrees F. This will take 1-2 hours if left alone, or speed up the process by placing the pot into a bowl of ice water for about 10-15 minutes. Check often with a thermometer. Spoon off any milk skin that has formed on top.
Add Yogurt Starter. Remove a ladleful of the warm milk into a bowl and whisk the yogurt starter into it. Then pour the mixture into the pot and whisk to combine.
Set Yogurt Timer: Place the inner pot back in the instant pot and secure the lid (again, it doesn’t matter if the vent is sealed or not). Press the “Yogurt” button and adjust until it reads 8:00 to 12:00 hours (less time for looser, milder yogurt and more time for thicker, tangier yogurt).
When the time is up, check the yogurt. You will know it’s ready when it has thickened and jiggles only slightly, like jello. (After refrigerating for a few hours it will set up even more.)
Refrigerate. Remove the yogurt to a container or cover the inner instant pot bowl and refrigerate for at least 4 hours or overnight, before serving. This allows the yogurt to thicken and set up more. Stir well before serving.
Store in containers in the fridge and enjoy within 10 days.
Yogurt starter: You need to use a yogurt starter or store-bought plain yogurt that has active cultures in it (most do). Check the label for the ingredients Lactobacillus bulgaricus or Streptococcus thermophilus.Do NOT use flavored yogurt! You can add flavor after the yogurt is made. (When testing this recipe I used plain, non-fat Greek yogurt).Milk: I use regular cows dairy milk from the grocery store (pasteurized milk). The higher the fat in the milk, the creamier and thicker the end result yogurt will be. Whole milk is preferred for the creamiest and thickest result, but I've had great success using low-fat milk.
Skim milk (non-fat): If using skim milk, add 6 tablespoons of yogurt starter instead of 1/4 cup and incubate for 10 hours. You may notice a layer of liquid on top when it’s finished incubating--just spoon it off and discard it.
Raw milk: I have not tested this recipe with raw milk, but I’ve read that the results can be inconsistent based on the microbes in the raw milk competing with the yogurt starter. Let me know if you try it with raw milk! Sheep milk and Goat milk could be also used but the yogurt will take on those respective flavors.
To make Greek Yogurt:After the yogurt is made place cheese cloth over a fine mesh strainer and set it on a large bowl. Pour the yogurt into the strainer and allow it to strain for at least 2 hours or up to 6. (If it strains for too long it will become closer to cream cheese, then yogurt). Scoop out the thick Greek yogurt and store in a container in the fridge for 7-10 days.Whey from the yogurt will drain into the bowl and it can be discarded or saved and used for protein smoothies or shakes.Doubling or halving the recipe:
Every 1 quart (4 cups) of milk need 1 Tablespoon of yogurt starter. If using more than 1 gallon of milk, you will need an 8 quart instant pot. To halve the recipe, use 1/2 gallon of milk and 2 tablespoons yogurt starter.
Storing and Freezing Instructions:Homemade yogurt will last stored in the fridge for 7-10 days, or can be frozen for up to one month. The frozen yogurt can act as a yogurt starter for future batches of yogurt. Thaw overnight in the fridge.