Crockpot Au Gratin Potatoes

4.84 from 31 votes

Crockpot Au Gratin Potatoes are the ultimate cheesy comfort food! Thinly sliced potatoes simmer in a rich, creamy sauce until perfectly tender. Perfect for holidays when oven space is tight or summer days when you want to keep the kitchen cool!

Prep Time30

Cook Time3

Total Time3 30

Course: Dinner, Side Dish

Cuisine: American, Vegetarian

Keyword: Crockpot Au Gratin Potatoes, crockpot potatoes au gratin

Servings: as a side

Author: Chelsea Lords

Cost: $7.53

Equipment

Crock-Pot 6-quart
Large pot nonstick

Ingredients

5 cups gold potatoes peeled and thinly sliced, see note 1
Salt and pepper
4 tablespoons unsalted butter
1/2 teaspoon garlic powder
1/2 teaspoon onion powder
1/4 cup all-purpose flour
1-1/2 cups milk I recommend whole—see note 2
1/2 cup sour cream I recommend full-fat
1-1/2 cups Cheddar cheese sharp or extra-sharp, see note 3
Fresh parsley or chives, optional, for topping

US - Metric

Instructions

Use a Crock-Pot liner or very generously spray your slow cooker with cooking spray. I used a 6-quart slow cooker. Smaller cookers may not be able to cook the potatoes evenly. If you use a smaller pan, you will have to halve this recipe.
Wash and peel the potatoes. Thinly slice potatoes about 1/8-inch thick. (I like to use a mandolin slicer for speed and accuracy.) Measure the potatoes to get 5 packed cups.
In a large nonstick pot, melt butter over low heat. Once melted, add garlic powder, onion powder, plus salt and pepper (I add 1-1/4 tsp salt and 1/4 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 the remaining 1/2 cup milk. Stir occasionally until mixture comes to a boil.
Once boiling, reduce heat to medium-low and stir constantly for 1–2 minutes or until mixture is nicely thickened (see note 4). Remove pot from heat and let cool for 2 minutes. Stir in sour cream until smooth. Stir in cheese, mixing gently until melted and smooth. Add sliced potatoes and stir to coat.
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 Crock-Pot (this will absorb lots of moisture and keep potatoes crispier), then place on the lid. Cook on high (low heat doesn’t work for this recipe) for 2-1/2 to 4-1/2 hours, depending on the slow cooker. Slow cookers cook at different temperatures; mine takes just under 3 hours—check occasionally to avoid burning the edges or overcooking the potatoes. (If you think of it, halfway through the cooking time, change out the paper towels for fresh ones. If not, don’t stress it.)
Once 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: Yukon gold (also called gold, Yukon, or yellow potatoes) are my favorite potato to use. Russet potatoes will also work. Peel potatoes, rinse in cool water, and use a mandoline slicer set at 1/8-inch thickness to cut the potatoes and measure to get 5 packed full cups.

Note 2: I like whole milk best; it delivers the richest end result. But 2% and 1% will work; I do not recommend skim milk or plant-based milk alternatives.

Note 3: Avoid pre-shredded cheeses as it will make the dish greasy. (Most pre-shredded cheeses have a wax/powder coating.) Use sharp or extra-sharp Cheddar to ensure plenty of flavor!

Note 4: 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.

Storage: Cool the potatoes, then store them in an airtight container in the fridge for up to 4 days. Freezing can affect the texture, but if needed, store in a freezer-safe container for up to 2 months.

Nutrition