The Key Differences Between Au Gratin And Scalloped Potatoes

If you love casseroles — those deep, bubbly, and often saucy or cheesy dishes baked in the oven until hot inside and browned on the top (via Uno Casa) — and you love potatoes, then we're willing to bet you love potatoes au gratin, scalloped potatoes, or both. Both dishes feature thinly sliced potatoes doused with some sort of rich milk or cream sauce, and both are baked in the oven until deliciously moist, with a slightly crisped crust, according to MasterClass. 

Both potatoes au gratin and scalloped potatoes are an indulgent starch option that go great alongside other comfort food dishes such as pork chops, sliced ham, meatloaf, or baked chicken. The two dishes have enough similarities between them that you might have actually thought they were one and the same, but in reality, they actually have some subtle differences. 

Let's take a look at what those differences are.

Scalloped potatoes and potato gratin are two very similar dishes — similar enough that you might have thought that they were two names for the same creamy, baked casserole dish featuring thinly sliced, tiled potatoes. But these are actually two classic potato dishes that utilize slightly different ingredients and techniques.

Let's start with potatoes au gratin. As the name implies, this is a French dish, thought to have originated in the Dauphiné region of the country (via The Spruce Eats). "Au gratin" means topped with breadcrumbs, cheese, or both (via Dictionary.com), so the final layer of a gratin usually features this mix, which turns brown and crispy in the oven. Underneath, MasterClass notes, the potatoes used in au gratin tend to be sliced a little more thinly than those used in scalloped potatoes, and more cheese (typically Gruyère) is sprinkled between those layers, creating a cheesy, oozy dish.

Scalloped potatoes, which, like au gratin, feature sliced potatoes in a hot cream or milk sauce, do not typically call for cheese. The dish should come out moist and creamy, but it won't be cheesy, and while its top will brown, it won't be super-crispy like potato gratin's. So while both these dishes are potato-laden crowd pleasers, you'll want to know exactly which one you decide to whip up for your next special dinner.