Sharing my personal chef secrets for how I do mashed potatoes for clients so they reheat beautifully and stay light and fluffy. Make-Ahead Mashed Potatoes (Mashed Potato Casserole) are smooth, creamy, slightly cheesy, garlicky, a little bit tangy and a whole lot delicious.
Best of all, they can be made two days ahead and baked when you need them or two hours ahead and kept hot in your slow cooker!
Why This Recipe Is a Keeper:
Sometimes referred to as a Mashed Potato Casserole, these Make-Ahead Mashed Potatoes are everything!
- Smooth and creamy
- Slightly cheesy
- A little bit tangy and a whole lot delicious
- A potato ricer takes care of any lumps
- Minimal stirring/processing keeps them light, fluffy and far from gummy.
This Make-Ahead Mashed Potatoes recipe is based on some food science put forth by Cook’s Illustrated (a membership site so I can’t link) and food scientist Shirley Corriher where butter goes into the potatoes before any other dairy is added. According to Cook’s Illustrated, adding melted butter first–before any liquid–coats the starch in the potatoes with fat so it can’t absorb liquid which is what leads to gluey mashed potatoes. Shirley Corriher says the fat from the butter gets absorbed into the cells of the potatoes first then the milk (or the rest of the dairy) loosens and flavors the potatoes. Here’s all the information at Food52 which I can link to: A Genius Trick for More Buttery-Tasting Mashed Potatoes.
Reheating the Make-Ahead Mashed Potatoes (Mashed Potato Casserole) in the oven makes them souffle-like and produces light, golden, crispy edges everyone will fight over! You can also keep them hot in your slow cooker for up to two hours.
I’ve made them this way hundreds of times for personal chef clients over 20 years and for my family with not a single complaint. My clients even freeze them and they still reheat beautifully.
So delicious you may not even need gravy, but if you do, be sure to add my No-Drippings Gravy!
Let’s make ’em!
How to Make Make-Ahead Mashed Potatoes:
Here’s everything you’ll need to make this make-ahead mashed potato recipe along with how to prep. See the recipe card below for the exact quantities.
- Russet Potatoes: Russet potatoes are my favorite potatoes for mashed potatoes because of their high starch content. Yukon Gold or red will work but their “waxy” nature can get gummy a little too quickly.
- Garlic: Fresh garlic is best but I have used a little garlic powder added to the melted butter in a pinch.
- Butter: I always use unsalted butter in cooking because I can control the amount of salt.
- Sour Cream: I use full-fat sour cream but light sour cream does work.
- Cream Cheese: Here too, full-fat but light cream cheese (Neufchatel) does work. Let soften before using in the mashed potatoes.
- Half-and-Half: I like half-and-half the best for mashed potatoes (half cream, half whole milk) and I always have it on hand because it’s what I put in my coffee.
- Gather and measure out all the ingredients.
- Spray a 13 x 9-inch baking dish or two smaller dishes with cooking spray.
- So that the potatoes don’t start discoloring before you get them all peeled, fill a pot with an estimated amount of cold water you think will cover the potatoes. You can add or remove water later but you want the water to just cover the potatoes.
- Then, peel the potatoes, rinse to ensure they’re clean and cut into even chunks and place in the water. (I usually cut them into 1 to 1 ½-inch chunks.)
- Add 8-10 peeled cloves of garlic in the water along with a generous amount of salt–approximately 1 tablespoon.
- Place the pot with the potatoes on the stove, turn the heat to HIGH, then place a stick of butter in a stainless steel bowl and set it over the potatoes.
- Keep an eye on the butter and remove it from the top of the pot when it is melted or almost melted. Do not let the pot boil over. Add 1 teaspoon salt then set the butter aside to cool. You can also do this in a small saucepan to pour over the riced potatoes.
- Cook the potatoes until they can be easily pierced with a paring knife.
- Drain well, then place back on the hot burner for just a couple minutes so any residual water steams away. You’ll notice the edges of the potatoes turning a little whiter.
- Then, working quickly so the potatoes don’t cool too much, start pushing the potatoes and garlic while they’re still hot and steaming into the melted butter. (I find disposable gloves help tremendously in handling the hot potatoes.)
- Keep going until you have all the potatoes “riced.”
- You still have to work quickly so the potatoes don’t cool and you end up with firm “riced” potatoes.
- Quickly stir the potatoes to incorporate and distribute the butter.
- Push the potatoes off to one side of the bowl.
- In the other half, place the sour cream, cream cheese and half-and-half.
- Puree the sour cream, cream cheese and half-and-half with an immersion blender avoiding the potatoes. Do not puree the potatoes with the immersion blender. A hand mixer also works to blend the sour cream, cream cheese and half-and-half but it takes longer. (You can also do this in a separate bowl then add it to the potatoes. However, this is how I do it at a client’s home to reduce the number of bowls and pots I use.)
- Then stir the potatoes into the sour cream, cream cheese and half-and-half blend.
- You may think you’re going to have potato soup, but it all comes together into a lovely creamy blend.
- Transfer the potatoes to the prepared baking dish(es). Cool and refrigerate.
- When ready to bake, preheat your oven to 375 degrees and bake until the potatoes are puffy, the top is lightly golden and the potatoes are thoroughly heated through.
Beautiful, poofy, fluffy Make-Ahead Mashed Potatoes!
Chef Tips and Tricks:
- When boiling potatoes, you always want to start with cold water. If you start with hot water or boil the water first then add the potatoes, the potatoes cook unevenly.
- Over the years of my personal chef career, I’ve had to learn how to reduce the amount of pots, pans and bowls I use and reduce steps. Placing the bowl with the butter over the pot of potatoes both melts the butter and helps the pot of potatoes boil a bit faster. However, as stated above, keep an eye on the butter so it just melts and so the potatoes don’t boil over.
Frequently Asked Questions:
Puree or blend the sour cream, cream cheese and half-and-half then place in a saucepan on the stovetop on low and very gently warm it before adding to the potatoes. Be careful to not scald the combination or boil it. Allow a little extra time to heat back up in the oven as they’ll cool down slightly.
You absolutely can–up to two hours. Set your slow cooker to LOW and preheat it while boiling and assembling the potatoes. Melt a little extra butter and lightly brush the slow cooker insert. When you have the potatoes all stirred together, transfer them to your slow cooker and cover. Remove the cover occasionally to release any steam and condensation that builds up on the cover.
You’re after the fat in the butter here to get into the cells of the potatoes and coat the starch. A small amount of separated milk solids won’t affect the quality of the potatoes.
You can, but I’ve never been a fan because it’s easy to over blend the potatoes which can cause them to become gummy.
These can be made two to three days in advance and refrigerated. Let cool thoroughly in the refrigerator then cover. If they’re still warm when you cover them, there will be condensation that builds up on the cover which can drip back down on the potatoes.
Absolutely! After assembling, place in oven-safe containers such as Pyrex or aluminum (if you’re okay with that). Cool thoroughly then freeze for 1-2 months. Thaw in the refrigerator then reheat uncovered in the oven at 375 degrees.
There are so many things you can do with this mashed potato casserole recipe! You can add:
- Roasted garlic
- Different types of cheese such as Cheddar, Gruyere, blue cheese or Parmesan
- Chipotle chiles or Hatch green chiles
- Rosemary or other herbs such as chives
- Caramelized onions
- Pretty much anything!
- Mississippi-Style Boneless Beef Short Ribs
- Slow Cooker Boneless Beef Short Ribs Bourguignon
- Roast Turkey Breast with Traditional Stuffing
- Turkey Scallopini in Sherry Cream Sauce with Mushrooms and Artichokes
- Braised Pork Loin Roast in Dijon Mustard Sauce
More potato recipes you can make ahead!
Get all my delicious potato side dish recipes at: Potato Side Dishes – From A Chef’s Kitchen
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Make-Ahead Mashed Potatoes (Mashed Potato Casserole)
- Cooking spray
- 5 pounds Russet potatoes - peeled and cut into 1 to 1 ½-inch pieces
- 8-10 whole cloves garlic - peeled
- 1 stick unsalted butter
- 1 package (8-ounce) cream cheese - room temperature
- 1 cup sour cream
- 2 cups half-and-half
- Freshly ground black pepper - to taste
- Spray a 13 x 9-inch baking dish (or two smaller baking dishes) with cooking spray.
- Place peeled potatoes and garlic in a pot of cold water to cover. Add a generous amount of salt (approximately 1 tablespoon).
- Set the pot on the stove burner and set the heat to HIGH. Place the butter in a stainless steel bowl and set it over the potatoes to melt the butter.
- Bring potatoes and garlic to a boil. KEEP AN EYE ON THE BUTTER and remove the bowl from the pot when the butter JUST melts and before the pot boils over. Add 1 teaspoon salt to the butter.
- Boil the potatoes uncovered until they can be easily pierced with a knife. Turn the heat off.
- Drain the potatoes then place the pot back on the OFF–BUT STILL WARM– burner for 1-2 minutes.
- Working quickly, push the potatoes through a potato ricer into the melted salted butter. Stir to distribute the butter and smooth out the "riced" potatoes.
- Push the potatoes to one side of the bowl. Place the cream cheese, sour cream and half-and-half in the other side of the bowl. Puree the cream cheese/sour cream/half-and-half blend with an immersion blender (DO NOT PUREE THE POTATOES). (Alternatively, use a hand mixer to smooth out the blend.)
- Stir the potatoes into the cream cheese/sour cream/half-and-half blend. (It will take a little while and you may think you have potato soup, but as the potatoes cool, they'll blend with the creamy blend.
- Transfer the potatoes to the prepared baking dish. Refrigerate until needed.
- When ready to bake, let potatoes sit out at room temperature for 30 minutes. (You never want to place a cold ceramic or glass dish directly into a hot oven.) Preheat oven to 375 degrees. Bake for 45-50 minutes or until heated through and the top is lightly golden.
These are estimated values generated from a nutritional database using unbranded products. Please do your own research with the products you’re using if you have a serious health issue or are following a specific diet.