This slow cooker 4-ingredient horseradish mashed potatoes recipe was born out of a spring brunch at my uncle’s house, when he specifically requested “something creamy but with a kick.” These potatoes are exactly that: ultra-smooth, boldly flavored, and surprisingly low-effort. Everything cooks right in the slow cooker while you handle the rest of your menu, and then you mash and stir in the horseradish and butter at the end for a fluffy, steamy side that feels a little special without any extra work. It’s the kind of recipe you keep in your back pocket for busy weeknights and holiday dinners alike.
Serve these horseradish mashed potatoes straight from the slow cooker on warm, with an extra pat of butter melting in the center for that picture-perfect pool of richness. They’re amazing alongside roast chicken, ham, grilled steak, or salmon, and they balance out anything smoky or salty really well. For brunch, I like to pair them with roasted asparagus, a simple green salad, and soft scrambled eggs. If you’re planning ahead, you can keep them on the warm setting for up to 2 hours and just give them a quick stir before serving.
Slow Cooker Horseradish Mashed Potatoes
Servings: 6

Ingredients
3 pounds russet potatoes, peeled and cut into 1 1/2-inch chunks
1 cup whole milk (or half-and-half for richer potatoes)
4 tablespoons unsalted butter, plus more for serving if desired
3–4 tablespoons prepared horseradish (not creamy style), to taste
1 1/2 teaspoons kosher salt
1/2 teaspoon freshly ground black pepper
Directions
Add the peeled, chunked potatoes to the bowl of a 4- to 6-quart slow cooker. Sprinkle the salt and pepper over the potatoes, then pour in the milk.
Cover and cook on HIGH for 3 to 3 1/2 hours, or on LOW for 6 to 7 hours, until the potatoes are very tender and easily pierced with a fork. The milk around the edges will look a bit bubbly and starchy—that’s perfect.
Turn the slow cooker to WARM or OFF. Add the butter directly to the hot potatoes and let it sit for a minute or two to melt slightly.
Using a potato masher, mash the potatoes right in the slow cooker until mostly smooth and fluffy, leaving a few rustic bits if you like. If you prefer a whipped texture, you can use a hand mixer on low speed for 30–60 seconds, being careful not to overmix.
Stir in 3 tablespoons of prepared horseradish, tasting as you go. If you want more heat and bold flavor, add up to 1 additional tablespoon. Adjust the salt and pepper if needed.
Smooth the mashed potatoes into a loose mound in the slow cooker. Use the back of a spoon to swirl the top, then add another tablespoon or two of butter in the center so it melts into a glossy pool. Cover and keep on WARM until ready to serve, up to 2 hours, stirring occasionally to keep them creamy.
Variations & Tips
For extra-creamy potatoes, swap the milk for half-and-half or use 3 tablespoons of butter instead of 4 if you want to lighten things up slightly. If you like a stronger horseradish punch, stir in an extra teaspoon or two right before serving so the flavor stays sharp. To make them ahead, cook and mash the potatoes as directed, then cool, cover, and refrigerate for up to 2 days; reheat in the slow cooker on LOW with a splash of milk, stirring occasionally, and refresh with a bit more butter and horseradish at the end. For a slightly different flavor profile, use Yukon Gold potatoes for a naturally buttery taste and creamy texture. If you need to keep things mild for kids or spice-sensitive guests, start with just 1 to 2 tablespoons of horseradish and serve extra on the side so everyone can customize their own bowl.