Place 2 cups of rice in a medium bowl and wash it three times. Place washed rice in the Instant Pot.
Add 1 cup of water and 4 cups of milk into the Instant Pot. It is important that you keep this ratio. This ratio of liquid to rice will ensure the rice cooking well, without burning the bottom and you will have a little extra liquid leftover. Water also helps the rice from sticking to the bottom of the pot. Stir ingredients together. DO NOT add sugar at this time. Adding sugar while rice is cooking will burn the bottom of your Pot.
Before you close the lid of the pot, make sure the silicone ring is nice a snug inside the lid. Set the Instant Pot to MANUAL and adjust the PRESSURE to LOW. Set the timer to 15 minutes. Close the lid of the pot and lock the pressure latch.
Once the time is up and your IP is beeping, turn OFF the system. Slowly turn the pressure latch towards venting. However, do not vent it right away. Keep on holding the pressure latch between lock and venting. This is done to avoid foaming of the milk through the valves. Trust me, it will save you a lot of mess. You can do a natural release after turning the IP off. It will just take a little longer.
Once the lid is open, stir the pudding. If you followed the recipe and used the same rice, the bottom of the Pot will be clear.
Add remaining 1 cup of milk and 1/2 cup of sugar. You can most certainly use less sugar if you wish. Stir ingredients together.
Add butter to the pudding and mix it well one more time. At this point, your pudding is fully cooked. If you would like to add other spices or dry berries, this is where you would do so. My kids enjoy rice pudding with just a little more butter.