Crockpot Au Gratin Potatoes are pure comfort food and these are the BEST! Thinly sliced potatoes in an ultra-cheesy cream sauce are slow cooked to tender perfection. Save that precious oven space during the holidays or prepare these in the summer while keeping the oven off and the heat out of the kitchen -- the slow cooker is a lifesaver for either scenario!
Course Dinner, Side Dish
Cuisine American, Vegetarian
Keyword Crockpot Au Gratin Potatoes, crockpot potatoes au gratin
PREP SLOW COOKER: Use a crockpot liner or VERY generously spray your slow cooker with nonstick spray. I used a 6-quart slow cooker for the recipe. Smaller cookers may not be able to cook the potatoes evenly. If you use a smaller pan, you will have to halve this recipe.
PREP POTATOES: Wash and peel the potatoes. Thinly slice potatoes about ⅛-inch thick. (I like to use a mandolin slicer for speed and accuracy.) Measure the potatoes -- you should have 5 packed cups.
CHEESE SAUCE: In a large nonstick pot, melt butter over low heat. Once melted, add garlic powder, onion powder plus salt and pepper to taste (I add 1¼ tsp salt + ¼ tsp pepper). Sauté 1 minute or until fragrant. Sprinkle in flour and whisk constantly for 1 minute until smooth (don't let it brown). Very gradually pour in 1 cup milk while whisking constantly. Once completely smooth, increase heat to medium-high and gradually add in the remaining ½ of milk. Stir occasionally until mixture comes to a boil.
SAUCE, CONT.: Once boiling, reduce the heat to medium-low and stir constantly for 1-2 minutes or until mixture is nicely thickened (SeeNote 5). Remove pot from heat and let cool for 2 minutes. Stir in sour cream until smooth. Stir in Cheddar cheese, mixing gently until melted and smooth. Add in the sliced potatoes and stir to coat.
SLOWCOOK: Transfer the mixture to the slow cooker and press in an even layer with the back of a spoon. Place 3 paper towels on top of the crockpot (this will absorb lots of moisture and keep the potatoes crispier) and then place on the lid. Cook on high (low heat doesn't work for this recipe) for 2½ to 4½ hours, depending on the heat of your slow cooker. Slow cookers cook at different temperatures; mine takes just under 3 hours -- check occasionally to avoid burning the edges or over-cooking the potatoes so they are mushy. (If you think of it, halfway through the cooking time, change out the paper towels for fresh ones. If not, don't stress it.)
ENJOY: Once the potatoes are tender and cooked through, remove the lid and gently stir the potatoes. Garnish with fresh parsley or chives and any additional salt/pepper as needed. Continue to cook without the lid for 15-20 minutes to get a bit crisper on top if desired. Enjoy promptly.
Notes
Note 1: Potatoes: Yukon gold (also called gold, Yukon, or yellow potatoes) are our hands-down favorite potato to use. Russet potatoes will also work. Peel potatoes, rinse in cool water and then use a Mandoline slicer set at 1/8th-inch thickness to cut the potatoes and measure to get 5 packed full cups. Note 2: Milk: We like whole milk best; it delivers the richest end result. 2% and 1% will work, but we do not recommend skim milk or plant-based milk alternatives.Note 3: Sour cream: We recommend full-fat sour cream so the sauce doesn't break (which it sometimes does with low-fat sour cream).Note 4:Cheese: Avoid the pre-shredded cheeses as it will make this dish greasy. (Most pre-shredded cheeses have a wax/powder coating.) Make sure to use sharp or extra-sharp Cheddar to ensure plenty of flavor!Note 5: Thickness check: The sauce should be thick enough to coat the back of a wooden spoon. Lift up the spoon and immediately trace a line across the back of the spoon with your fingertip. If the line retains a clear track, the sauce is thick enough. If not, the sauce needs to be cooked a bit longer.