Peel potatoes and chop them into small chunks. Add potatoes to slow cooker and add water.
Cook on low for 6 hours or on high for 3-4 hours.
Once potatoes are soft, drain water. Mash quickly with a potato masher.
Add milk, butter, salt, pepper, or whatever else you like to add to mashed potatoes and beat with an electric mixer until they reach your desired taste and consistency.
Set your slow cooker to warm until you are ready to eat, then enjoy!
Make Ahead Mashed Potatoes
After cooking, add an extra dose of milk and butter, so that the potatoes are kind of... soupy. This would not be ideal if you were eating them right away, but this will ensure that after being refrigerated, they will still be soft and creamy.
Put them in a deep casserole dish and store in the fridge overnight. Warm them up in the oven the next day, uncovered, with a little butter on top.
Transfer the mashed potatoes back into the slow cooker, and set it to low. Do this for up to 4 hours, stirring once an hour. Stir before serving. The mashed potatoes will stay warm and creamy.
Don't over-mash your potatoes. Mash until they are soft and creamy, then stop.
You can add other mix-ins to these potatoes. Some of our favorite things to add are sour cream, cream cheese, garlic, chives, dill, or rosemary.