Clean the potatoes skin and cut them in halves or quarters depending on the size.
Place the trivet (or mesh steamer basket) in the bottom of the Instant Pot and add the water, potatoes, and salt in the Instant Pot.
Set to manual preset, on high pressure for 13 minutes.
While it is cooking, place the butter, garlic powder, celery seed, black pepper in a medium sized saucepan and on medium heat melt the butter and mix until all spices are combined.
Once the butter is all melted remove from heat and set aside.
Once the Instant Pot is done, turn the valve for quick release.
Pull the potatoes out (discard water) and place them in a large mixing bowl.
Mash the potatoes with a potato masher or a hand-mixer.
Pour in the butter mixture and mix until blended.
Once the mixture is all combined, add the sour cream and milk. Mix until combined.
Serve as desired and add toppings!
How do you store mashed potatoes after cooking?You can store pressure cooker mashed potatoes in the fridge for up to 3-5 days. Make sure that you use an airtight container when refrigerating so your potatoes stay fresh for a longer period of time.