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I am mkaing Potato Gratin and want to know if I can slice the poatoes 4 hrs early?

I am wondering if I can slice potatoes 4 hrs earlier then when I need them. If I can how would you store them?


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  1. I would go ahead and slice them and keep them in cold water until you are ready to use them.

    1. Yep, submerge them in cold water (and I'd put them in the frig) or they're going to get black and slimy.

      1. Try slicing them into cold water, and I imagine they should hold, though they will lose quite a bit of starch to the soak. Make sure they are completely covered or you'll have browned spots. I can't vouch they'll go four hours without browning, as I've never soaked them as long as four hours. So, to be honest, I can't tell you I KNOW this will work. Anyone else have more experience?

        2 Replies
        1. re: amyzan

          What about soaking them in the heavy cream you're going to use for the gratin? I could be wrong, but I imagine that this might improve the thickness of your sauce because you won't actually lose the starch... :)

        2. A tbsp. of white vinegar added to the soaking water will prevent oxidizing but may give a slight vinegary flavor.(lemon juice works, too....) Adam

          1. Sorry to be the contrary voice, but I wouldn't soak in water--you need the potato starch to thicken the cream. I'd bet that you can assemble the whole thing, cover, and pop into the fridge till it's time to bake.

            4 Replies
            1. re: Erika L

              Yep -- this is the way to go.

              1. re: Erika L

                Yep, Erika L has it right. If you put your potatoes in cold water to hold they'll lose a lot of starch and your gratin will be disappointing. I'd wait until it was about time to deposit them in the oven before getting started on it.

                1. re: Erika L

                  excellent, that's alot easier, can't belive I didn't think of that .

                  1. re: drewb123

                    Better yet, go ahead and bake the gratin ahead of time. It's one of those dishes that reheats beautifully - I actually prefer it that way.

                2. Only four hours. I have stored them over night in water and never had a problem with loss of starch.

                  1. In the cook book, French Classics, Richard Grausman says: If you prepare the potatoes ahead of time, slice them, soak them in the milk and cream in which they will be cooked so as not lose the starch.
                    Maybe you can put them in the baking dish you are going to bake and this will save more time tranferring them later too.

                    2 Replies
                    1. re: cpw

                      I have my Gratin prepared unfortunately my husband didnt get home till very late so I have yet to make it. Is it okay to stay in fridge prepared to go in the oven until tomm?

                      1. re: drewb123

                        As long as your potatoes are protected, submerged, so they don't brown, it should be fine. As someone mentioned above, this dish reheats superbly, so you may want to just go ahead and bake it 3/4, and then reheat with a little fresh cheese on top -- which is actually a better plan.

                    2. Just make the whole dish ahead. Sometimes I make mine the night before, put in the refrigerator and then bake when ready. Never had a problem. A few hours before absolutely. It's not hard I do it for dinner parties all the time. Not once did I not have it come out perfect. I did always cover good with saran wrap first tightly, then foil.

                      1 Reply
                      1. re: kchurchill5

                        What do u recc reheating potatoes at? I want to make a gratin to bring to a catering event tomm and was wondering if A) I could bake for an hr like the recipe calls for and then B) pop it in the oven tomm for the last 45 min like the recipe calls for. Here is the recipe if it helps.