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These creamy Instant Pot Mashed Potatoes are made with fluffy russet potatoes, whole milk, sour cream, and plenty of butter. Ready to serve in about 40 minutes, they’re an easy, delicious side dish for everything from weeknight meals to special holiday dinners!
The Instant Pot makes preparing mashed potatoes super simple. Unlike my classic mashed potatoes, which are boiled on the stovetop, this version steams them right in the Instant Pot until perfectly tender. They’re then gently mashed and combined with warm butter, milk, and sour cream. The result is rich, buttery mashed potatoes with the most delicious, pillowy-soft, creamy texture.
Quick Look: Instant Pot Mashed Potatoes
- Method: Four pounds of peeled and chopped russet potatoes steam in a 6-quart Instant Pot using a steamer basket and 1 cup of water.
- Flavor: Rich, buttery, and just a little tangy from sour cream.
- Time: Approximately 40 minutes from start to finish, including 8 minutes of high-pressure cooking.
- Good to know: This recipe makes 8 generous servings and uses a full cup each of butter, whole milk, and sour cream. They’re rich, yes, but that’s the point!
- Best for: Weeknight dinners, holiday meals, and large family gatherings when stovetop space is limited. The Instant Pot frees up a burner and keeps the potatoes warm until you’re ready to serve.
Table of Contents
Ingredients and Substitutions
These Instant Pot mashed potatoes use simple, easy-to-find ingredients. For the complete list of ingredients and measurements, see the recipe card at the bottom of the post.
- Russet potatoes: My go-to for mashed potatoes. They’re what my dad used to make his mashed potatoes, so they’re what I use. Russets have a high starch content and relatively low moisture, making them ideal for soft, fluffy mashed potatoes that readily absorb butter and milk. Yukon Gold potatoes are another good option, although they’ll produce a naturally denser, creamier texture. To learn more, check out my post waxy vs. starchy potatoes where I explain the difference.
- Water: The water isn’t actually added to the potatoes. Instead, the potatoes sit in a steamer basket above the water. The water turns to steam inside the Instant Pot and ultimately cooks the potatoes.
- Butter: One of the reasons these mashed potatoes taste so good is because we’re adding two whole sticks of butter. Salted or unsalted butter both work. I typically prefer salted butter, but using unsalted gives you more control over the final seasoning.
- Whole milk: Adds moisture and richness without making the potatoes feel overly heavy. Half-and-half is an excellent substitute if you want an even richer result.
- Sour Cream: This is one ingredient I never leave out. Sour cream adds richness along with a subtle tanginess that balances all that butter. I recommend full-fat sour cream for the best flavor and texture. Full-fat plain Greek yogurt can be substituted, although the flavor will be slightly different.
- Salt and black pepper: Start with approximately 1 teaspoon of kosher salt, then taste and add more as needed. You may need a little less if you’re using salted butter, or more if you’re using unsalted. Add freshly ground black pepper to taste.
How to Make Instant Pot Mashed Potatoes
I made these mashed potatoes in my 6-quart Instant Pot Ultra, which is no longer available. A great alternative is the 6-quart Instant Pot Duo. Other 6-quart Instant Pot models with a high-pressure setting should work similarly, although the time required to reach pressure may vary.
You’ll also need a steamer basket or suitable trivet, a potato masher, and a small saucepan for warming the butter, milk, and sour cream.
- Prepare the potatoes and Instant Pot: Place a metal trivet or steamer basket inside the stainless steel insert of your Instant Pot. Pour 1 cup of cold water into the bottom. Peel the russet potatoes and cut them into approximately 1- to 2-inch chunks, keeping the pieces similar in size so they cook evenly. Transfer the potatoes to the steamer basket, keeping them above the water.
- Pressure cook the potatoes: Secure the Instant Pot lid and turn the steam release valve to the sealing position. Select High Pressure and set the cooking time to 8 minutes. The Instant Pot will take approximately 15 minutes to come to pressure before the 8-minute countdown begins. Once the cooking time is complete, carefully move the steam release valve to the venting position for a quick release. When the pressure has fully released and the float valve has dropped, remove the lid. The potatoes should be very tender and break apart easily when pierced with a fork.
- Drain and return the potatoes to the Instant Pot: Carefully lift the steamer basket out of the Instant Pot and allow the potatoes to sit for 1-2 minutes so excess steam and moisture can escape and drain away. Meanwhile, discard the cooking water and wipe the stainless steel insert dry. Return the potatoes to the Instant Pot, ready for mashing.
- Mash the potatoes: While the potatoes are still hot, use a potato masher to break them apart until there are no large chunks remaining. You don’t need to mash them until they’re perfectly smooth at this point. The warm butter, milk, and sour cream will help bring everything together in the next step. I prefer a traditional potato masher over an electric mixer. It gives me more control over the texture and helps prevent overworking the potatoes.
- Warm the butter, milk, and sour cream: In a small saucepan set over medium-low to medium heat, combine the butter, whole milk, and sour cream. Warm gently, stirring occasionally, until the butter has melted and the mixture is smooth and warm. Don’t let it boil. Warming the dairy before adding it to the potatoes makes it easier to incorporate and helps keep the mashed potatoes hot and creamy.
- Combine: Set the Instant Pot to the Keep Warm setting. Pour the warm butter, milk, and sour cream mixture over the mashed potatoes. Using your potato masher or a sturdy spatula, gently combine everything until the potatoes are creamy and the dairy has been fully incorporated. Be careful not to overmix.
- Season and serve: Start with approximately 1 teaspoon of kosher salt and freshly ground black pepper to taste, adjusting the seasoning as needed. If the potatoes are thicker than you’d like, add a little additional warm milk until they reach your preferred consistency. Serve immediately with extra butter and a sprinkle of sliced green onions or fresh chives, if desired.
Storage, Freezing, and Reheating
To store: Allow the mashed potatoes to cool slightly, then transfer them to an airtight container and refrigerate for up to 3-4 days. For larger batches, divide the potatoes among smaller, shallow containers to help them cool more quickly. Refrigerate within two hours of cooking.
Can You Freeze Instant Pot Mashed Potatoes? Technically, yes, but I don’t usually recommend it. Mashed potatoes can lose some of their smooth, creamy texture after freezing and thawing, becoming grainy or watery. The sour cream may also separate, affecting the consistency. While the generous amount of butter in this recipe can help the potatoes hold up better during freezing, there’s still a chance the texture won’t be quite the same once reheated.
How to Reheat Instant Pot Mashed Potatoes
Mashed potatoes tend to thicken as they cool, so add a splash of milk, cream, or homemade chicken stock when reheating. Milk or cream helps restore their rich, creamy consistency, while chicken stock adds moisture and a little extra flavor. Add a bit of butter, heat gently, and stir only as needed to avoid overworking the potatoes.
- Oven: Transfer the mashed potatoes to an oven-safe baking dish. Add a splash of milk or cream and a few pats of butter, then cover tightly with aluminum foil. Reheat at 350°F for approximately 20-30 minutes, or until heated through, stirring gently halfway through.
- Stovetop: Place the mashed potatoes in a saucepan over low heat with a splash of milk or cream. Cover and heat gently, stirring occasionally to prevent sticking. Add more liquid as needed.
- Microwave: The microwave is actually my preferred way to reheat mashed potatoes because it’s so fast and easy. Transfer individual portions to a microwave-safe bowl, add a splash of milk, and cover loosely. Heat in 30-60 second intervals, stirring between each, until hot throughout.
Instant Pot Mashed Potatoes FAQs
For this recipe, 4 pounds of peeled and chopped russet potatoes cook at High Pressure for 8 minutes, followed by a quick release. You’ll need to allow approximately 15 minutes for the Instant Pot to reach pressure, so the entire recipe takes about 40 minutes, including preparation, cooking, and mashing. Making more or fewer potatoes? The pressure-cooking time generally stays the same as long as the potato chunks are approximately the same size. Larger batches may take longer to reach pressure, while smaller batches may take less time. Just be sure not to exceed your Instant Pot’s maximum fill line.
Absolutely! Prepare the mashed potatoes 1-2 days in advance, refrigerate, and gently reheat with a splash of milk or cream and a little extra butter. If serving later the same day, use the Instant Pot’s Keep Warm setting, making sure the potatoes stay at or above 140°F. For another make-ahead holiday option, try my mashed potato casserole.
Technically, no, but I highly recommend one. A steamer basket keeps the potatoes above the cooking water and makes them easy to remove once tender. I use this steamer basket with silicone-wrapped handle for easy lifting. A metal trivet also works, provided the openings are small enough to keep the potato chunks from falling through. Otherwise, you can cook the potatoes on the stovetop using my guide to boiling potatoes.
Yes, but the mashed potatoes will have a more rustic texture. Plus, russet potato skins are relatively thick, so I usually peel mine. If you enjoy skin-on mashed potatoes, Yukon Golds are a great alternative because their skins are thinner and more tender. Be sure to scrub them thoroughly before cooking.
More Mashed Potato Recipes
Looking for another easy Instant Pot side dish? My Instant Pot mashed sweet potatoes are another delicious option, especially for holiday dinners. And if you love potatoes as much as I do, try my crispy oven roasted potatoes next, or browse all my potato recipes for more delicious ways to prepare them.
Did you try this Instant Pot mashed potatoes recipe? I’d love to hear how they turned out! Leave a comment and recipe rating below, and let me know if you made them for a holiday gathering or an everyday family dinner. Thank you so much! 💛
Instant Pot Mashed Potatoes Recipe
Ingredients
- 4 pounds russet potatoes, peeled and chopped into 1- to 2-inch pieces
- 1 cup cold water
- 1 cup (2 sticks) butter, salted or unsalted, plus more for serving
- 1 cup whole milk, or half-and-half, plus more as needed
- 1 cup full-fat sour cream, or plain Greek yogurt
- 1 teaspoon kosher salt, to taste
- Freshly ground black pepper, to taste
- Sliced green onions or chives, for garnish (optional)
Instructions
- Set up the Instant Pot: Place a steamer basket or metal trivet inside the stainless steel insert of a 6-quart Instant Pot. Pour in 1 cup of cold water, making sure the water sits below the steamer basket.1 cup cold water
- Prepare the potatoes: Peel the russet potatoes and cut them into evenly sized 1- to 2-inch pieces. Arrange the potatoes in the steamer basket, keeping them above the water.4 pounds russet potatoes
- Pressure cook for 8 minutes: Secure the lid and turn the steam release valve to the Sealing position. Select Pressure Cook (or Manual) and set to High Pressure for 8 minutes. Note: Allow approximately 15 minutes for the Instant Pot to build pressure before the cooking timer begins.
- Release the pressure: When the cooking time is complete, carefully turn the valve to Venting for an immediate quick release. Once all pressure has escaped and the float valve drops, remove the lid. Carefully lift the steamer basket out of the Instant Pot.
- Rest the potatoes: Allow the potatoes to rest in the basket for 1-2 minutes so excess steam and moisture can escape and drain away. Discard the cooking water and wipe the stainless steel insert dry. Return the cooked potatoes to the pot.
- Partially mash the potatoes: Using a potato masher, gently mash the hot potatoes until they're about halfway mashed, with some small chunks remaining. Avoid mashing them completely smooth at this stage.
- Warm the butter, milk, and sour cream: Add the butter, whole milk, and sour cream to a small saucepan over medium-low heat. Stir occasionally until the butter has melted and the mixture is smooth and warm. Do not allow it to boil.1 cup (2 sticks) butter, 1 cup whole milk, 1 cup full-fat sour cream
- Finish mashing and season: Set the Instant Pot to Keep Warm. Pour the warmed dairy mixture over the partially mashed potatoes and continue mashing gently until the butter and dairy are fully incorporated and the potatoes reach your desired consistency. For thinner mashed potatoes, add a little additional warm milk.
- Season and serve: Add approximately 1 teaspoon of kosher salt and freshly ground black pepper to taste. Adjust the seasoning as needed. Serve immediately with extra butter and sliced green onions or chives, if desired.1 teaspoon kosher salt, Freshly ground black pepper, Sliced green onions or chives
Notes
- Steamer basket: A steamer basket is recommended to keep the potatoes above the cooking water. A metal trivet also works, assuming the potato pieces won’t fall through.
- Cooking more or fewer potatoes: The 8-minute pressure-cooking time generally stays the same as long as the potato pieces are cut to approximately the same size. Larger batches may take longer to reach pressure. Do not exceed the Instant Pot’s maximum fill line, and follow your model’s minimum water requirements.
- Butter and salt: Salted or unsalted butter works. Start with approximately 1 teaspoon of kosher salt and adjust to taste, depending on the butter and salt you’re using.
- For the creamiest texture: Warm the butter, milk, and sour cream before adding them to the partially mashed potatoes. Mash gently until creamy, but don’t overmix, which can make the potatoes gummy.
- Make ahead: Prepare 1-2 days in advance and refrigerate in an airtight container. Reheat gently with a splash of milk or cream and a little additional butter. Refrigerate leftovers for up to 4 days.
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Nutrition
Nutrition information is automatically calculated, so should only be used as an approximation.
