Reheat Casserole in the Oven or Microwave for Deliciously Moist Leftovers: 5 Simple Steps

If we're honest, we've enjoyed casserole leftovers for breakfast, lunch, and dinner time, and again - it can make an unconventional breakfast, but a delicious one! There is an art to reheating a casserole without letting it dry out - follow our simple guide to reheat casserole below!

How to Reheat Casserole in Oven or Microwave

Reheating a slice? Try the microwave!

The reheating method you choose depends on the size of your casserole. If you're simply warming up a slice of the casserole for breakfast the next morning, use the microwave - we microwave casserole slices because it's much easier to warm small portions without drying out your piece. 

To microwave a cold casserole slice, place it in a microwave-safe dish and cover it loosely. Do not use plastic wrap to cover your casserole dish, as it may melt in the microwave. Instead, place another plate on top of the dish, or use a hard plastic dish cover for use in the microwave. 

Microwave in 30-60 second increments until warmed to your liking - usually, 2 minutes is more than enough time to make your casserole piping hot!

Reheating a whole casserole? Use the oven!

If you're reheating casserole from refrigerator temperatures that's already cooked, you'll want to watch how you reheat it, as some casseroles dry out upon second heating. Instead, follow these simple instructions and learn how to warm up a refrigerated casserole perfectly!

Step #1: Remove the casserole from the fridge to warm before cooking. 

For the best results, remove your casserole from the fridge 30-60 minutes before baking it. This step is essential to keeping your casserole in the oven for as little time as possible while promoting even heating and protecting your bakeware. 

We love the results we get with our cast-iron casserole dish, as it keeps the casserole deliciously moist and is nearly indestructible. One thing cast-iron doesn't like is thermal shock or sudden temperature changes. Putting a cold cast-iron pan in a hot oven may cause your dish to crack, rendering it useless. No bueno!

Step #2: Preheat the oven.

Preheat your oven to 350°F, a nice, middle-of-the-road temperature which won't give your casserole a burnt top or cause it to dry out as it reheats. Place your casserole into an oven-safe container if it isn't already in one. 

Step #3: Cover your casserole with foil.

Your casserole's top already bubbled to perfection the first time it cooked and trying to achieve the same results the second time around ends with you trying to eat a dried-out loaf of your casserole's former glory. 

Instead, you need to tightly cover the casserole dish with aluminum foil as you reheat, with the option to take the foil off in the last 10 minutes of cooking to up the casserole's crisp-factor. 

Step #4: Leave the casserole to cook for 20-30 minutes or until hot throughout. 

Reheating times for casseroles vary based on overall size and ingredients, so you'll want to keep an eye on your casserole temperature more than watching how long it cooks. 

Give your casserole a stir midway through the cooking process to help the dish heat evenly. 

How long to reheat casserole in oven?

Generally, most casseroles reheat within 20-30 minutes, or when the temperature reaches 165°F, making it safe for consumption and enjoyably hot! 

Check your casserole's temperature once you hit the 20-minute mark with an oven thermometer - if the casserole isn't yet at 165°F, replace the foil and keep cooking, checking every five minutes. 

Step #5: Carefully remove and serve your delicious reheated casserole!

Once your casserole hits 165°F and looks ready to eat, be sure to use oven mitts to remove the extremely hot casserole dish from your oven. 

Slice, serve, and enjoy your casserole leftovers with your friends and family!

How long can I keep my casserole in the fridge?

We don't care to admit we've played this dangerous leftover game before, so for food safety concerns, do better than us - eat your refrigerated leftover casserole within three days of cooking. Otherwise, you're taking some chances, and trust us; it's not worth it. 

If you don't think you'll get through a casserole fast enough, toss it in the freezer! Which brings us to...

Can I freeze a cooked casserole?

Yes! Freezing a cooked casserole is a great way to make an easy dinner for a busy day when you're out of time. The only catch when working from frozen is that you need to give it time to defrost before you reheat frozen casserole. 

Take your frozen casserole out of the freezer and place it in the fridge 24 hours before you cook it or try to bake it straight from frozen in the oven. If you bake frozen casserole, follow the steps above, but keep in mind the baking time will be much longer if you're working with a frozen casserole, and transfer the frozen casserole to a warmer baking dish, or one that can withstand rapid temperature changes. 

Final Notes & Our Favorite Tips & Tricks

When you're reheating anything baked, like casserole, keep the goal in mind - you want to warm the food, not cook it until bubbly. If you try to reheat your casserole for too long, the dish's fats may separate from the sauce or cheese, causing an oily mess in the dish. 

You can also cut between your casserole portions before you reheat it to help the center heat more quickly, which lessens the chance you'll overcook your leftovers. 

Following our steps above, we hope you enjoy your perfectly moist and crispy-topped casserole leftovers again and again!