Casseroles are a favorite in our house. These dishes are easy to prepare, delicious, and can serve a crowd easily. I'm sure we've all had leftover casserole at some point. Fortunately, there are tricks you can use to avoid drying out a casserole when you reheat it.
As a general rule your oven, microwave, or air-fryer are the best ways to reheat your casserole. Keep the casserole moist by placing a small bowl of water alongside the dish.
You'll be a casserole reheating pro you have all the more reason to make extra casseroles just for the purpose of stocking the freezer with leftovers to reheat later.
Reheat a casserole in the oven for best results
Reheating a casserole in the oven is the method of choice for myself and most of our recipe testers. The texture and flavor stay really good, you save on dishes, and it's easy to pop into the oven and go attend to another chore while it reheats. This method works best when reheating an entire casserole versus individual portions.
- Set the casserole out for 30 to 60 minutes prior to reheating it in the oven.
- Preheat the oven.
- If the casserole looks particularly dry, add a small amount of water to it to help rehydrate the casserole. I usually add about 2 Tablespoons and drizzle the water along the very edges of the pan where the casserole tends to dry out fastest.
- Cover the casserole tightly with a cover or aluminum foil to help retain moisture.
- Simply reheat, not recook the casserole. Most casseroles require at least 20 minutes to reach a temp of 165 in the center.
- Optional: If your casserole has toppings that are meant to be crunchy remove the cover from the casserole in the last few minutes of reheating. Or turn on the broiler, remove the cover, and broil the casserole until the topping crispens up. Be mindful to watch to see if your baking dish can handle the broiler temp.
Reheat a casserole in the microwave for best results
Reheating casserole in the microwave works great for individual portions. I use this method most often when heating leftovers for myself for lunch. In fact, in some instances, I'll simply separate the large leftover casserole into smaller portions to store in the freezer.
- Be sure to use a microwave-safe dish.
- Reheat a single portion at a time. If you want to reheat an entire casserole at one time I would recommend using the oven method, instead.
- Loosely cover the casserole. Usually, I use a paper towel or plastic wrap slightly opened.
- Microwave at 30-second intervals stirring in between each time. About 1 minute 30 seconds to 2 minutes will be enough for most casseroles.
- To help keep/add moisture in your reheated casserole add a small bowl of water alongside your plate. The water will add steam to the microwave and help keep your casserole hydrated.
Reheat a casserole in the air fryer for best results
The air fryer reheats my leftovers without leaving them soggy or losing any flavor. The air fryer is fast, easy to clean, and a tool completely underutilized for reheating food. If you have an air fryer you should be reheating your casserole in it! Like the microwave, the air fryer works best to reheat smaller portions.
- Be sure to thaw your casserole if you are using the Air Fryer for reheating.
- Preheat the Air Fryer to about 400F.
- Turn the heat down to 325F. I like to have the temp for the Air Fryer set lower than the temp I would use for the oven to help make sure my casserole doesn't dry out.
- Place your leftovers in the basket.
- Cook for about 3-5 minutes or until the leftovers are hot enough to your liking. Your toppings should remain crispy. Yay!
Store Your Leftover Casserole Properly
How you store your leftover casserole will play a big role in how yummy the casserole is when you reheat it, regardless of the method. Consider how you plan to reheat your casserole when you store it and you'll find your meals are easier, tastier, and more efficient!
| Type of container | Storage location | Reheating Method | Tips: |
|---|---|---|---|
| Aluminum Pan with cover | Freezer | Oven | Best for reheating entire casseroles. Perfect for gifting casseroles. |
| Ziplock Bag | Freezer or Fridge | All | Best for freezing individual portions. Be sure to thaw in the fridge for 24 hours. |
| Plastic Storage | Fridge | Microwave or Air Fryer | |
| Original Casserole Pan | Fridge | Oven | Best for reheating the entire leftover casserole. Add a small bowl of water alongside to add moisture. |
| Microwave or Air Fryer | Best for reheating small portions. |
Can you heat a frozen casserole?
If you want to heat a frozen casserole I recommend using the oven method to ensure even heating. Be sure to preheat the oven and add a considerable amount of time to the cooking temp. In most cases, I have found to need at least 1 hour and often 1.5 hours to heat a casserole. Always check to make sure your baking dish can handle the shock of going from the freezer to the oven.
If you are thinking far enough ahead I would recommend you take the casserole out of the freezer 24 hours prior and let it thaw in the fridge. Then, 30 to 60 minutes prior to heating set it on the counter to thaw further.
Letting the casserole thaw allows for a more even heat distribution through the casserole and allows your casserole to heat up faster. Also, a good amount of bakeware can't handle the shock of going from the freezer straight to the oven.
How to moisten a dry casserole
Oh Oh. You baked your casserole and it is dry. Ugh. Before you reheat your casserole you have a perfect opportunity to introduce additional liquid and fix it. Gently stir in chicken broth or water. If you can't easily stir it in gently drizzle it around the top and edges of the casserole. Don't forget to add a small bowl of water alongside the casserole while it reheats so it doesn't further dry out.
How much liquid you stir in will depend on the size and type of your casserole. For a 9 by 13 casserole I find that ¼ cup of liquid is always acceptable if that helps give you a starting point.
Reheating a Casserole Mistakes
- Using a slow cooker to reheat your leftovers is a bad idea because the temp doesn't get above the recommended 170F degrees fast enough to be considered safe.
- Reheating more than once should be avoided because the temperature fluctuation is unsafe. Also, each time you reheat you lose the flavor and texture of the food.
- Not covering the casserole in the oven will dry out the casserole. Use aluminum foil to create a cover, if needed.
- Reheating too long (essential baking it a second time) will change the casserole's integrity. You might find fats begin to separate, the noodles get gummy, and the veggies overbake. Try to simply heat the casserole and remove it from additional heating.
Do you have a Toaster Oven?
I don't personally have a toaster oven but if you have one...
Melanie recommends:
I usually reheat casseroles in single serving sizes in our toaster oven. I haven't particularly noticed if it changes/affects the original quality but I don't get complaints from the family lol. Besides, aren't casserole's always better as leftovers 
