While mashed potatoes are best enjoyed once they are prepared, you can refrigerate the leftovers and heat them later. You can also prepare the mashed potatoes ahead of time and add the other ingredients the next day in the crock-pot to prevent ruining the texture. When you heat the mashed potatoes, you can restore the texture and flavor that you might lose from refrigerating the side dish by adding more butter or milk. Heating the mashed potatoes in the crock-pot will increase the temperature slowly to prevent the potatoes from becoming lumpy.
Keep the mashed potatoes in the refrigerator in a covered container until you are ready to heat them.
Transfer the mashed potatoes to the crock-pot. Add butter or seasonings to the mashed potatoes if you desire.
Set the crock-pot to the low setting. Place the lid on the crock-pot.
Stir the mashed potatoes often while they reheat. This will ensure that they stay smooth.
Heat the mashed potatoes until they are hot. Add ingredients like butter or milk to achieve your desired constancy. Add these ingredients slowly and stir the mashed potatoes to avoid adding too much.