6 tips to help you cook the best scalloped potatoes you'll ever eat

Scalloped potatoes are one of those dishes that used to appear regularly around family dinner tables but for some reason, people just don't make it as much anymore. And that's a shame because there's nothing better than thinly sliced potatoes swimming in milk and butter (unless you crumble bacon on top which, in that case, makes them even better!)

Maybe one of the reasons scalloped potatoes aren't served as much these days is because people can't get them quite right. Maybe the potatoes are too thick, or perhaps their milk always curdles when they try to make them from scratch. But while it's true that a number of things can go wrong when making scalloped potatoes, follow these tips and you'll get it right so this comforting casserole can appear on your table more often!

1. Choose the right potato
Any potato dish calls for the right kind of potato to be used, and there are many different kinds. For scalloped potatoes, choose waxy, thin-skinned potatoes such as long white potatoes or red-skinned potatoes. Waxy potatoes have a lower starch content than other types such as Yukon Golds and they also have a higher water content. Both of those things will help the potatoes retain their shape so you don't end up with a casserole dish of mushy potatoes but just perfectly scalloped ones.

2. Use a mandoline to slice those potatoes super thin
A great scalloped potatoes dish should only include potatoes that are super thin, as it allows them to cook evenly and gives a nice potato:sauce ratio. But it can be difficult to get them that thin with a knife alone. Instead, use a mandoline slicer that will get the potatoes super-thin and make your scalloped potato dish the best it could possibly be. Many people are intimidated by mandolines because that blade is super sharp and if you're not careful, you could do some serious damage to your fingers or hand. Always make sure you use the hand guard, as this will let you slice the potatoes quickly and easily, without worrying about how many bandages you have on hand.

3. Don't let the potatoes become discolored
Potatoes can discolor quite easily. If you're peeling a lot of them for the dish, as the oxygen hits the sliced potatoes it will discolor them wherever the air hits. There's no need to worry about this kind of discoloration, as it will go away as the potatoes cook; but if you're worried about it, just place the slices into a bowl of cold water while you continue to slice the rest of them.

But discoloration can also occur during the cooking time. If you're using an aluminum or iron pan (such as a cast iron), the metal in the pan will cause an acidic reaction in the potatoes, and this can discolor them. Instead, use only glass or ceramic casserole dishes to have potatoes that aren't only delicious, but also provide for a nice presentation.

4. Don't let the milk curdle
Taking out a beautiful scalloped potatoes dish only to find the the milk has curdled can be disheartening. And there are a number of reasons why it can happen. The first is that the heat may be too high, which makes the proteins in the milk bind together, causing lumps. To avoid this, make sure to cook scalloped potatoes in a gentle heat - about 325 degrees Fahrenheit is perfect.

If you're going to be adding onions or garlic as so many scalloped potato dishes call for, cook them slightly first. That will release some of their acid, which can also cause milk to curdle when cooked together.

Lastly, the type of milk you use is important. Use whole, high-fat milk, or even substitute half of the milk for cream. The higher the fat content, the less likely the dairy will curdle when cooked. And make sure that whatever milk or cream you're using is very fresh, as older milk and cream are more likely to curdle.

5. Cook only until potatoes are tender
It's not just meat that can be overcooked; casseroles can be, too. And if you overcook your scalloped potatoes, the milk is not only likelier to curdle, but the potatoes will break down into complete mush. And neither will make for an appealing dish. Instead, cook the dish gently just until the potatoes are fork-tender. With this simple trick, you'll know that your scalloped potatoes are perfectly cooked.

6. Let it rest
Most casserole dishes need to be rested, and this is an important step when making scalloped potatoes, too. Not only will it be far too hot to eat straight out of the oven without severely burning the roof of your mouth, but it also won't be as good as it could be if you don't let it rest. As it rests, the dish will set a little bit, letting those potatoes hold together better and ensuring that every scoop will be saucy instead of all that delicious sauce falling to the bottom of the casserole dish.