At this point, you can either bake it right away or refrigerate the casserole overnight and for up to 24 hours. During this time, the flavors mingle together and the bread has a chance to soak up some of the liquid and flavor.
Unless food will be frozen, it's safest and will provide the best quality product to start preparing most perishable foods no more than a day before a meal. For example, assemble a vegetable casserole a day in advance, refrigerate and then bake the day of your dinner.
If you've got raw egg yolks or whites left over from a recipe which you don't want to waste (let's face it, why would you?), you can store them in the fridge as long as you plan to use them within the next few days.
The following foods will keep 3 to 4 days in the refrigerator: Fully cooked ham slices. Cooked meat and meat casseroles. Cooked chicken and chicken casseroles (Learn more about how to tell if chicken is bad)
Cover casserole with plastic wrap or aluminum foil and refrigerate for at least 30 minutes and up to 24 hours.
The reason is simple: the cold casserole dish may crack. Despite being able to withstand extreme temperatures, vessels made from ceramic, glass, or enameled cast iron undergo thermal shock when they're pulled from a cold fridge (or freezer) and added directly to a hot oven — who knew?
Although it takes a little bit longer, it's worth the extra time for the best eggs you can serve. I recommend scrambling your eggs as the very first step in breakfast prep, and then cooking them last, which should fill the 15-minute rest time nicely.
As much as possible, consume raw eggs foods immediately after preparing them. Only keep raw egg dishes for one day and refrigerate at all times.
If the casserole has raw protein (meat, poultry, seafood), you should cook it thoroughly before freezing. Line the baking dish with enough aluminum foil so that there is an overhang on all sides. After cooking, let the hot casserole cool a bit, then carefully remove it from the pan by lifting the foil on both sides.
Your vegetables could be to blame
According to Allrecipes, the vegetables you selected are the most common culprit for your watery casserole, due to the high percentage of moisture that some of them contain in their raw form which seeps out as they cook down in your dish.
If you need to make your casserole further in advance, prepare it two or three days ahead of time and refrigerate.
In reality, you can keep the batter up to 48 hours without any problem, but never longer as the eggs and raw milk can contain salmonella that is not killed by the cold and it could lead to food poisening. Don't forget to cover with plastic wrap or the milk will absorb the different smells in your refrigerator.
You can microwave it until it's hot, one serving at a time, or you can reheat the whole casserole in a 350°F oven for 15 to 20 minutes until it's heated through. Do you have a favorite breakfast casserole combo?
Most recipes suggest 350 °F. Bake until the center of the casserole reaches an internal temperature of 160 °F as tested with a food thermometer. After baking, any leftovers must be refrigerated within two hours and can be kept three to four days in the refrigerator or frozen for about three months.
Leftover raw egg whites and yolks should be put in airtight containers and stored in the refrigerator immediately. To prevent yolks from drying out, cover them with a little cold water. Drain the water before using.
The United States Department of Agriculture does not recommend eating raw shell eggs that are not cooked or undercooked due to the possibility that Salmonella bacteria may be present. However, homemade mayonnaise can be safely made if raw, in-shell pasteurized eggs or pasteurized egg products are used.
Make-Ahead or Frozen Scrambled Eggs
According to the American Egg Council, you can crack and mix the eggs together up to two days in advance and store them in the refrigerator without quality suffering.
Leave scrambled eggs on the heat too long, and you'll find yourself with a plate of dry, tough, rubbery eggs. Likely a far cry from the fluffy eggs you were hoping for. Yes, it's important to make sure eggs are fully cooked before diving in, but take care than you don't leave the pan on the heat for too long.
In the case of casseroles, leftovers should actually never be added to a preheated oven. The reason is simple: the cold casserole dish may crack.
And another word on preheating: Pyrex recommends only placing their bakeware in an oven that's already heated. These dishes are designed for the heat of the oven, of course, but the company explains that pans “can break when exposed to the direct heat element while the oven is preheating.”
Pyrex is oven-safe up to 425 degrees. However, direct contact with heating elements can cause the glass to shatter or break. Pyrex is not oven-safe when used under the broiler or in a toaster oven.