Can you prep potatoes ahead?

I wouldn't leave them standing in water longer than overnight. They tend to go a weird colour and a bit slimy!

I make ice box mashed potatoes. I make them the weekend before, cover, then put them in the oven on Thanksgiving. That way the mess is all cleaned up and gone before Thanksgiving.

Here's a recipe...
Ice Box Mashed Potatoes

I would and have done with no ill effects. I agree with all the reasons not to that have been stated so far but I change the water daily and store them in the fridge and all is well. I've probably kept them for up to 4 days when necessary.

I would not leave them soaking in watet, but I would fully make them ahead of time. I usually make 10 pounds of potatoes for Thanksgiving, and I make them a day or two before and put them in a crock pot the day of. It saves me so much time on Thanksgiving day!

I have only ever done the day before myself. Great idea about using a crockpot to cook them in.

The only time I freeze them as if I have too many leftovers, and then I freeze them to use at a later time. I usually cut up a stick of butter and. That over the top of the potatoes when I reheat them in the crockpot. I know some people add a little milk, but I have never done that.

My family loves the Pioneer Woman's mashed potatoes and they can be made 1 or 2 days ahead and reheated. You can lighten them up a bit by substituting lower fat versions of the dairy.

thepioneerwoman.com/cooking/delicious_creamy_mashed_potatoes/

When I worked at a restaurant during my early 20s, we would peel the potatoes in a big steel drum, then cut them up and we covered them with cold water and added some sort of powder and placed in the fridge. I can't for the life of me remember what the powder was. But it kept the potatoes fresh for a couple of days. I wonder if Google will have anything.

A few years ago I read this trick in a magazine (Bon Appetit or Food & Wine maybe), mash the potatoes a few days in advance, fold in about a 1/4 cup of mayo and they reheat amazingly. I know I had problems prior to this where reheated potatoes weren't as creamy if reheated. But the mayo really works and you can't taste it.

I'm always looking for ways to cut down on the cooking on Thanksgiving, and I try to make as much in advance as possible. Good luck!

 leaving them in water for that long is not a good thing. just boil, cool them, then put them in an airtight container in the fridge until you mash and season them.   I'm making duchess potatoes this year and I'm going to do the same thing until thanksgiving when I just mashing, seasoning, and piping before putting them in the oven.

Bake them, cut them open, scoop out the insides. This is how we make mashed potatoes, it's so much easier and they won't get runny. Just make sure you leave enough time for them to cool a bit so you don't burn your hands.

This is what I'd do with having to make so much.

I don't peel the red potatoes that we use.

No! Don't do it! (I guess unless you test the tips other Peas have mentioned.)

Just last week I did this. My son needed a dish for a potluck at school. We decided on scalloped potatoes.
Because he leaves at 7:00 am, I had to get they dish in the oven at 6:00 am

I thought I was being so cool by peeling and slicing the potatoes the night before and then covering and leaving them in the fridge.

When I pulled them out, like 7 hours later... they were slimy and gray. Like dark ugly gray!!

They were the last of my potatoes, so I had to use them. I guess they still tasted good. The kids ate them (high school age), but we're a bit weirded out by the color!!!