Select the "Sauté" function on your Instant Pot, and select the "less" option for the lowest sauté temperature. Set the timer for 60 minutes.
While the Instant Pot begins to heat, cut your butter into 1-2" cubes.
Once the Instant Pot is heated thoroughly, add the cubed butter to the insert of the Instant Pot.
Stir the butter with a wooden spoon until it is completely melted.
Once the butter is melted, a low simmer will begin, and you will see foam and milk solids begin to rise to the surface. Use a skimming ladle or metal spoon to remove the milk solids. I like to place mine in a small container and use in mashed potatoes or to top roasted chicken. You do not need to stand close by and skim all the foam as it rises, just come by every so often and skim off what has risen to the surface.
Milk solids will continue to rise to the surface. Continue to skim them as they do. If the heat ever becomes to high and the butter begins to boil, lower it to the warm function and proceed with the remaining instructions.
Keep skimming the milk solids every so often as they rise, until there are no more milk solids and foam and the resulting product is a golden liquid. If you are opting for a clarified butter, you can strain at this point. If you are wanting to make ghee (removing the water, as well as milk solids), wait for the remaining milk solids on the bottom to turn a toasty golden color. Then, you may strain. Once you have made "ghee" the bottom will have a light brown color, and the liquid will be shimmering, rather than simmering. This is because the smoke point of ghee is much higher than butter, so it is acting as a stable oil at this point.
Fit a medium sized bowl with a nut milk bag or a fine sieve lined with cheesecloth. Pour the ghee through your method of straining. This additional step helps remove all of the milk solids from the ghee, ensuring there is no casein left behind, and helps extend the storage life. I have also found success with using a clean pour-over coffee maker and a coffee filter, although it takes much longer.
Remove the nut milk bag or strainer, leaving all of the ghee behind. Discard the remaining milk solids and transfer the ghee into clean, glass jars fitting with an airtight lid. I like to sterilize mine beforehand to ensure a long storage without spoilage.
Store at room temperature for up to 3 months (if using sterilized jars). Once opened, move to the refrigerator. I prefer to store mine in the refrigerator, since it will be good for 6-12 months and I don't have to worry one bit. Just use clean spoons and knives when you take out your ghee for cooking.