The hardest part about making au gratin potatoes in the crockpot is patiently waiting while you smell all that melting cheese and garlic.

If you’ve ever baked scalloped potatoes the traditional way, you know that they take a long time. There’s always a risk of under-cooking the potatoes in the center, and that can be stressful when your mission is a simple, comforting side dish.
It’s so much easier in the crock pot! Everything stays moist and the potatoes get crispy around the edges.

I can’t believe it’s taken me this long to try it, especially when I grew up eating scalloped potatoes with polish sausage on a weekly basis.

Au Gratin vs Scalloped
To cheese or not to cheese? Both au gratin and scalloped potatoes are thinly sliced and layered with a roux-thickened white sauce made from butter, flour, and milk. Scalloped potatoes often involve cream and have a little bit of a milder flavor profile with no cheese; whereas, au gratin potatoes contain cheese.

Now that we got that out of the way…
Which Cheese Is Best?
When it comes to cheese and potatoes, you can hardly go wrong. I like to grate medium to tangy medium-firm cheeses, depending on how I’m serving the potatoes.
Gruyere is a classic choice and has a nutty, creamy, and rich profile. Sharp cheddar has a bit more of a stretchy or string quality and has a nice tanginess, which is bolder. I might choose cheddar if serving with bacon and green onion.

Which cheese you choose is more about what you hope to accomplish. I might choose gruyere for a traditional Thanksgiving side dish because it will work well with stuffing and turkey. Cheddar or cheddar jack might make for a bolder side dish with some crisped bacon and green onions.
How Thick To Slice the Potatoes
My mom used to make paper thin sliced scalloped potatoes, but I decided to cut mine thicker. Use a mandolin if you have one, aim for 1/4-inch thick slices.

Making Au Gratin Potatoes in the Crock Pot
- It’s important to season each layer of the potatoes with salt and pepper so that the depth of flavor is distributed throughout.
- Pour the cheese sauce over the top and just let the sauce work its way down.
- Set timer to 4 hours, high heat.
Technical Tip: In testing this recipe, I liked the texture after 3 1/2 hours, but I think 4 hours would make the consistency a bit more scoop-able.
More Slow Cooker Favorites
- Forever Barbacoa – Mexican Shredded Beef
- Crockpot Pork Green Chili
- Cuban Ropa Vieja (Shredded Beef)
- Green Chile Chicken Crockpot
For this recipe, I use a 5-quart crock pot. If your slow cooker has a larger or smaller capacity, you may find that the potatoes cook faster or slower, respectively.

Au Gratin Potatoes Crockpot Recipe
Equipment
- 5-quart crock pot
Ingredients
- olive oil for coating crock pot
- 2 tsp sea salt
- 2 tsp freshly ground black pepper
- 3.5 pounds Yukon Gold potatoes (5 large) peeled and cut into 1/4-inch slices
- 6 tbsp unsalted butter
- 1/4 cup all-purpose flour
- 2 garlic cloves minced
- 1/2 tsp onion powder
- 1 3/4 cups milk skim, 2%, or whole
- 1/2 cup full fat sour cream
- 1 1/2 cups Gruyere cheese shredded
- 1 tbsp fresh parsley or chives for garnish, minced
Instructions
- Rub the inside of a 5-quart crockpot with olive oil to coat. Mix the salt and pepper in a small ramekin. Set the potato slices inside the crockpot and sprinkle with a large pinch of the salt and pepper mix. Repeat with the rest of the potato slices, seasoning between each layer.
- Melt the butter in a small pot over medium heat. Add the flour and stir for 2 minutes until very bubbly. Add the garlic and onion powder. Stir and cook an additional 2 minutes until the roux turns golden in color. Add the milk and stir well. Add the sour cream and cheese and stir to form a thick sauce.
- Pour the cheese sauce over the potatoes (do not stir). Program for high heat for 4 hours.
- After 3 1/2 hours, the sauce will be hot and bubbly and the potatoes will be tender all the way through, but I recommend an extra 30 minutes for a more scoop-able consistency. Serve with a sprinkle of fresh herbs. Taste and adjust salt as needed.
Nutrition
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