Potato Gratin - Hints/Tips
I made a potato gratin once and was not happy with it - a soupy mess. I would like to make another one for easter this year. I don't have a gratin dish - I will have to use a 9x13 pyrex baking dish.
I have come across recipes that call for -
- russet and yukon gold potatoes.
- covering the dish while it bakes
- not covering the dish.
- all cream, a mix of cream and milk, flour added to milk
- par cook potatoes first in cream
- simmer cream before adding to potatoes
I will have to make it the day before and reheat it at my parents house - will this be OK? about how long and at what temp should I reheat. Any hints/tips would be greatly appreciated.
I always make a basic white sauce- heated milk added to a roux, with a big of nutmeg salt and pepper then add grated gruyere then pour over potatoes and bake, uncovered.
I often make it in a skillet as well, so dont worry about not having a gratin dish. IF you make it ahead, I would reheat covered in foil at 300.
A different hint/tip: I never peel potatoes for gratins. It's not necessary if they are sliced very thin. You keep the nutrients and fiber and save unncessary work. I don't need the immaculate purity of peeled potatoes in a gratin, and they are usually hidden in dairy anyway.
Another tip from John Thorne in his essay on roasted cod with potatoes: you can hand cut peeled potatoes into thin wedged chips - that is, with a thin edge and a slighter thicker opposite edge. The thin edge tends to dissolve a bit and thicken any dairy (which helps when the dairy is milk, which curdles more than cream (the lower the fat, the higher the tendency to curdle over sustained heat).
re: Karl S
hmmm. If what you say about cudling "the lower the fat, the higher the tendency to curdle over sustained heat" is true, you might of solved my mystery and annoying problem of curdlng milk in the scalloped potatoes I've had. My way around that has been to make mornay sauce and adding cheese to that...
re: chef chicklet
With milk or lower fat creams, the protein content is higher, and therefore the risk of curdling when it's exposed to prolonged heat. The solutions are: (1) best - less milk protein, or (2) starches or fats that envelope and bind the proteins. That's why in food service, milk-based soups (infamously, chowders) are adulterated with thickeners (a chowder should really not be thickened with binders other than the potato starch and some butterfat from a touch of cream or butter, but binders make it easier to idiot-proof a chowder recipe....)
The most important aspect of making a nice gratin is getting the liguid the right texture before covering your potatoes. I always mix heavy cream with chicken or lobster stock(about 75-25). After i butter my gratin, the leftover butter goes into the liquid, along with garlic(sometimes rosemary or thyme) along with a little salt and pepper. I bring this up almost to a boil then reduce the heat and simmer until thick and reduced(coats the back of a spoon) about 40 minutes.
Take your buttered gratin dish out of the freezer and start layering your potatoes than cover with cream mixture/cheese until your desired thinkness. I start them covered @ 375ish for 50ish minutes. Then removed the foil and cook for 20 more minutes. The cooking times will vary depending on the side of your gratin/pan.
If you plan to reheat the following day, let potatoes come to room temp, than put in a 325ish covered for 30 minutes or until hot.