How to freeze leftover mashed potatoes and preserve their creamy texture

• Leftover mashed potatoes can be frozen for up to two months.
• Adding extra fat, like cream or butter, before freezing can help mashed potatoes retain their texture.
• Frozen mashed potatoes can be reheated on the stovetop, or in an oven, microwave, or slow cooker.

Mashed potatoes are one of those crowd-pleasing side dishes that you can never quite have too much of — until you do make too much, and you're not sure what to do with the leftovers. Fortunately, experts say those spuds don't have to go to waste, because you can freeze them. The first thing to know about freezing mashed potatoes is that the process may affect their texture.

"The liquid absorbed by the potatoes while cooking will form ice crystals when they are frozen," says Martha's Vineyard- and Boston-based personal chef Carlos Montoya. "This may make them mushy, soggy, or grainy."

That said, Montoya notes that there are things you can do in the cooking and freezing process that will help the mashed potatoes maintain their consistency. For one, he advises always using Idaho (russet) or Yukon gold potatoes — they freeze better due to their low moisture and starch content.

Below, experts share more must-know tips about freezing, thawing, and reheating mashed potatoes.

How to freeze mashed potatoes

For safety reasons, always freeze mashed potatoes within two hours of cooking them. This will prevent the growth of bacteria that can lead to foodborne illness.

Petranka Atanasova, the food blogger and recipe developer behind Sunglow Kitchen, recommends placing mashed potatoes in a freezer-safe container or plastic bag. If you have a large batch of leftovers, Montoya says you can divide them out into 1-cup portions before freezing them. This makes it easier to thaw only what you need.

When it comes to avoiding freezer burn, the less air in the container the better, says Montoya. Squeeze extra air out of plastic bags before sealing them. If you're using plastic containers, Montoya suggests either filling them to the top or placing a piece of parchment paper over the potatoes before closing the container.

Quick tip: Chefs say the best way to preserve the texture of mashed potatoes is to add more fat, which acts as a protective coating. If you know in advance that you're going to be freezing leftovers, Atanasova recommends adding double the amount of butter or cream that the recipe calls for. Otherwise, add more fat right before freezing them.

How long do frozen mashed potatoes last?

According to the US Department of Health & Human Services, frozen mashed potatoes are good for up to two months. However, Atanasova recommends eating them within a month — the more time the potatoes spend in the freezer, the more likely the consistency has been compromised.

You'll be able to tell if your mashed potatoes have gone bad after thawing them, says Atanasova. If they smell sour, or the liquid has separated from the solid and it doesn't combine when mixing, you should toss them.

Quick tip: Be sure to label the plastic bag or container of mashed potatoes with the date you froze them so you know when they've expired.

How to reheat frozen mashed potatoes

Ideally, Montoya says you should thaw mashed potatoes by placing them in the refrigerator overnight — this way, they'll not only heat up faster but also cook more evenly. If you don't have the time, though, experts agree that you can still reheat them straight from the freezer using any of the following methods

Stovetop: Place the mashed potatoes in a small pot over medium-low heat, and add a splash of milk, cream, or half and half. Stir frequently so the potatoes don't burn on the bottom of the pan, says Montoya.

Microwave: Add mashed potatoes to a microwave-safe bowl and cover them with a towel or lid. Montoya advises microwaving them on 50% power in one-minute increments until hot.

Oven: Preheat the oven to 350 degrees Fahrenheit, add the mashed potatoes to an oven-safe bowl or a pan, and cover them with a lid or aluminum foil. Cook them for 18 to 20 minutes, stirring halfway through.

Slow cooker: Atanasova recommends first pouring a splash of cream into the bottom of the slow cooker to prevent the mashed potatoes from sticking. Then, add the mashed potatoes and cook them on low for three to four hours, stirring at least once an hour.

Quick tip: If your mashed potatoes are too watery after reheating, Atanasova says they probably just need more cooking time for the liquid to evaporate. You can also try adding a small amount of cream cheese thicken them.

Insider's takeaway

Once you freeze mashed potatoes, you can reheat and enjoy the leftovers for up to two months.

The best way to preserve their texture is to add a little extra fat before freezing them and minimize their exposure to air in the plastic bag or container.

Heat up leftovers on the stove or in the oven, microwave, or slow cooker. The slow cooker method takes the longest while microwaving is the fastest — and cooking them on the stovetop will require the most attention, as you'll need to keep stirring them.

Regardless of which method you use, adding a splash of milk or cream to the potatoes can help revive their texture.