Oysters can cause food poisoning if not handled or stored properly. Shucked oysters keep safely in a refrigerator set to 40 degrees Fahrenheit for just 1 to 2 days, according to the USDA. If you prepare scalloped oysters ahead and store it in the refrigerator, it's best to do so the night before you serve it. If you leave it much longer, the dish may taste bad and may even pose a health risk.

It's safer to cook scalloped oysters before refrigerating. This involves mixing the freshly shucked oysters with the rest of the ingredients and cooking in a heavy frying pan. Spread the cooked mixture into a deep baking tray, with no more than two layers of oysters to ensure all of the shellfish cooks evenly. Cook for around 20 minutes, depending on the recipe and tray size. Scalloped oysters usually have a crumbed breadcrumb and cracker topping, but it's best to add this when reheating just before serving.

Once cooked, transfer your scalloped oysters to the refrigerator as quickly as possible. Never leave food out for longer than two hours before refrigerating. Cover the dish with aluminum foil or a tight lid. When you're ready to reheat the food, cook it until it reaches 145 F in the center; according to the FDA, this is the minimum internal temperature necessary for safety's sake. This typically means baking for at least 10 minutes in an oven set to 450 F.

You can freeze and keep scalloped oysters for 3 to 4 months before thawing and reheating. Just transfer the mix to a sealable plastic container. However, don't expect the same light, crunchy taste of a fresh batch; frozen oysters tend to turn soft and gooey, and so do the cracker crumbs in the topping. If you choose to freeze scalloped oysters, do so before adding the crumbed topping; otherwise, you'll end up with a mushy dish.