How to Reheat a Casserole in the Oven (the 6 Best Ways)

Today, I’m sharing how to reheat casseroles in the oven and the 6 best ways to reheat them so they’ll taste as good as the day you made them!

Casseroles are a delicious and convenient way to make and serve a one-dish meal for the family or a large group to enjoy.

The only better way to enjoy a warm and cozy casserole is to be able to enjoy a leftover casserole the next day for a quick and easy, relaxing dinner.

Paula Deen’s Green Bean Casserole

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Casseroles are also great to make ahead in advance and stored for a ready made meal of a whole casserole that is so handy for a busy weeknight.

What makes a casserole a casserole

Casseroles are usually layered in a baking dish consisting of meat, vegetables and a binder like a rice or pasta then covered with a yummy sauce or cheese.

It is then baked in the oven allowing the flavors to meld together and develop for a delicious dish of comfort food and bubbly goodness.

Reheating casseroles can actually enhance the flavors of a dish by allowing them more time to meld together and develop in the fridge.

John Wayne casserole in a white baking dish with a wooden spoon.
Cheesy John Wayne Casserole

What is a hotdish

In the Midwest region of the United States casseroles are often referred to as a “hotdish”.

Smoke Gouda potatoes au gratin in a white baking dish.
Smoked Gouda Potato Au Gratin – Photo: Happy Holiday Recipes

Best reasons you want to make a casserole

  • Convenience: easy one pot dish to enjoy anytime
  • Comfort Food: warm, hearty, filling and comforting for cold nights
  • Feed a Crowd: low budget-friendly able to feed large groups
  • Versatility: easily able to customize for your own personal preferences
  • Variations: so many different type of casserole they never get boring
  • Leftovers: best thing is to reheat them without preparing a new meal

Our favorite casseroles

What to serve with your reheated casserole

Sometimes you may want something more to enjoy with your reheated delicious casserole, some easy great ideas:

How to reheat a casserole

As with a lot of our reheating needs today the best way to reheat a casserole is in the hot oven.

But, with our busy lives that is not always the best or convenient way for someone to use.

We have the 6 best ways or different methods to reheat a casserole with the best tips.

It really depends on the amount of time you have, the size of your leftover casserole dish or size of the portion and appliances you may have access to.

Note: It is important to check with a food thermometer or an instant-read thermometer that the internal temperature of a casserole is 165°F for good casserole safe eating!

Reheating Casseroles in the Oven

The oven method provides the best even heating particularly for an entire casserole or a large portion and if you are using a large casserole dish.

Ruth's Chris sweet potato casserole in a small bowl with remaining casserole in the background.
Ruth’s Chris Sweeet Potato Casserole

The oven is the best way to reheat a casserole, reheating method:

  • Step 1: Preheat the oven to 350°F ensure your dish is oven-safe
  • Next Step: Cover the casserole: with aluminum foil on top of the dish to help prevent the dish from drying out
  • Place in: preheated oven, cook for 20-30 minutes depending on the size or thickness of your dish
  • Check the dish: for desired level of doneness
  • Remove from oven: once the casserole is fully heated remove and allow it to cool for a few minutes before serving

Oven temperature for warming casseroles

It is best to use the right temperature to make sure you have the best even cooking all the way through, avoiding cold spots.

Use a moderate temperature of 350°F not a common mistake of high temperatures for the cooking process.

How long to reheat a casserole in the oven

Remember we are reheating a leftover casserole in the oven not recooking the casserole!

In most cases reheating leftover casseroles will take 20-30 minutes to warm up depending on the size or thickness.

A larger or thicker casserole may require 25-35, or in some cases 35-45 minutes.

Start checking for your desired level of doneness at the 20 minute mark then every 5 minutes when you feel it is close to ensure it does not get dry or overcooked.

Cheesy taco pasta in a white baking dish with a spoon.
Taco Pasta Casserole

Should you cover a casserole when reheating

Yes, you should cover your casserole to prevent the dish from drying out as well as helping it to cook more evenly.

Use an oven-safe lid that fits your casserole dish or aluminum being sure to seal the edges of the foil tightly to trap the heat and moisture inside.

Can you put a cold glass dish in the oven

No, it is not the best idea to put a cold glass dish from the fridge of freezer right into the oven.

The sudden change in temperature or temperature shock could cause the glass to break or crack.

Allow your oven-safe glass dish to come to room temperature for 30-60 minutes before putting int the oven.

Philly cheesesteak casserole in a white baking dish.
Philly Cheesesteak Casserole

How to reheat an egg casserole or breakfast casserole in the oven

  • Allow dish from fridge to reach room temperature
  • Preheat oven: to 350°F
  • Cover with foil
  • Bake: for 20-25 minutes, checking for your level of doneness
  • Remove: when cooked through allow it to cool

How the reheat a tuna casserole in the oven

  • Allow the casserole to sit at room temperature for 30-60 minutes
  • Preheat oven to 350°F
  • Cover dish with aluminum foil
  • Bake for 20-25 minutes reheating time
  • Remove foil cooking it for an additional 5-10 minutes for crispy top
  • Once heated though allow to cool and enjoy

Convection oven: what dish to use and how to reheat a casserole

Reheating a casserole in a convection oven is similar to reheating in a regular oven but you get the added benefit of more even, convection cooking.

You can use oven-safe dishes that are made to withstand high oven temperatures made of glass, ceramic or metal dishes avoid any plastics.

Tip: For best results it is also a good idea to use a shallow dish that allows the hot air to circulate evenly around the food.

Steps for convection oven casserole reheat:

  • Step 1: Preheat convection oven to 325°F ensuring dish is oven-safe
  • Cover with foil: to prevent drying out
  • Place in oven: cook for 15-20 minutes
  • Check: for your level of doneness
  • Remove: from oven allow to cool and enjoy
Dorito chicken caserole in a white baking dish with a wooden spoon.
Cheesy Dorito Chicken Casserole

How to reheat a casserole without it drying out

Best Practices to avoid a classic casserole becoming a dry casserole:

  • Allow casserole to reach room temperature before cooking
  • Add Moisture with water dish: you can add moisture by adding an oven-safe dish with water to help steam the casserole in the oven.
  • Add moisture with liquid: add a little bit of liquid like water, broth, sauce or milk then layer foil on top creating a steam bath to help keep the casserole moist in the oven.
  • Add cheese to help create moisture.
  • Cover the casserole: Cover with foil or a lid to help avoid moisture loss
  • Use a lower temperature: You can reheat at 325°F will help it from drying out and cook more slowly but evenly
  • Do not overcook: Overcooking a casserole will dry it out

Reheating a casserole in the oven is the best way to enjoy leftover casseroles without losing any of the original texture or flavor.

Reheat casserole in microwave

When in a hurry or you do not have access to an oven, the microwave oven is a great option to reheat your casserole in smaller pieces or single portion.

Steps for reheating casserole in microwave:

  • Step 1: Transfer smaller portions to a microwave-safe dish that is not too deep
  • Cover the dish: with a microwave -safe lid or microwave save plastic wrap to help trap the heat and steam the dish to prevent from drying out
  • If dry: you can add a small amount of water, or broth before covering
  • Microwave on high: for 2-3 minutes if not heated through cook for 30 seconds to 1 minute addtional time
  • Remove the dish: once it is heated through stir if you can if it will not ruin the texture of the dish
  • Let cool: for 1-2 minutes before eating
Cheesy tortellini casserole in a blue and white baking dish.
Tortellini Alfredo Casserole with Broccoli

How to reheat a casserole in Air fryer

The air fryer is becoming a more essential item in a lot of kitchens for good reasons as it is a great addition for reheating a casserole with a crispier finish.

Steps for reheating casserole in an air fryer:

  • Step 1: Preheat the air fryer to 350°F for even cooking
  • Transfer to dish: that is oven-safe that will fit the air fryer basket or a silicone air fryer insert or you can put it directly in the basket
  • Cover dish: with foil to prevent drying out or burning, you may take the cover off for the last minute of cooking for crispier top
  • Place in basket: cook for 3-5 minutes may need additional minutes
  • Check: if heated through for your desired level of doneness
  • Allow to cool: serve at once

Can you put a casserole dish in the air fryer

Yes, you can as long the dish if heat resistant and an oven-safe dish that will fit in your air fryer basket not touching the sides. Make sure if using a lid it does not block the air circulation inside the air fryer.

Some air fryers are designed to fit different size and shapes of cookware including casserole dishes.

If your casserole dish does not fit in your air fryer you can transfer it to an oven-safe dish that will fit into your air fryer using the correct cooking times.

Cooking times will vary with thickness of your casserole and power of your air fryer but reheating your casserole with an air fryer is an easy, quick way.

Reheating casserole with Slow Cooker

Reheat your casserole in a slow cooker it a great idea if you’re looking for a time-saving way to reheat your casserole.

Steps to reheat a casserole in slow cooker:

  • Step 1: transfer casserole to slow cooker
  • Add liquid: if casserole is dry add water, sauce or broth but not so much to make it soupy
  • Set to low: cook slow cooker with a lid for 2-3 hours
  • Check: for your level of doneness
  • Stir: once heated through stir if you can to not ruin the texture
  • Enjoy!

Reheating your casserole in the slow cooker is a convenient and easy way.

Reheat a casserole in skillet

Using the top of the stove with a skillet is another great way to reheat your casserole if your oven is already occupied.

Steps for reheating casserole in a skillet:

  • Transfer casserole: to skillet of saucepan large enough to fit
  • Add Liquid: if you feel your casserole is dry or has thickened in the fridge you can add water or broth
  • Heat: cook over medium heat stirring to prevent it sticking to the pan
  • Cook for: 10-15 minutes until heated through
  • Enjoy

The skillet is a good method to reheat your casserole as you can control the cooking temperature quickly and stirring to help get even cooking.

Ravioli casserole in a red and white baking dish.
Baked Ravioli Alfredo

Reheat casserole in Toaster oven

Cook small portions or a slice of your casserole in the toaster oven:

  • Step 1: Set temperature to 350°F and sit your piece of casserole on wrap in a foil place on baking tray.
  • Make sure nothing is touching the cooking element
  • Cook for 5-8 minutes watching for doneness.
  • You can remove foil for last 1 minute of cooking for crispier top

Reheat casseroles with a crispy topping

Reheating a casserole with a crispy topping can be tricky as you want to make sure the topping stays crispy while it heating evenly through.

  1. Oven method: Preheat your oven to 350°F, cover with foil and bake for 20-25 minutes. Remove the foil and bake for another 5-10 minutes to crisp up the topping.
  2. Broil method: Preheat your broiler on high. Place the already heated casserole under the broiler for 2-3minutes or until the top is golden and crispy. Watch closely it will quickly burn.
  3. Skillet method: Cut the casserole into individual portions placing them in a non-stick skillet. Heat on medium heat, covered, for 7-10 minutes or until heated through. Remove the cover cooking for an additional 1-2 minutes to crisp up the topping.
  4. Air fryer method: Preheat your air fryer to 350°F, put it the air fryer basket and cook for 3-5 minutes, or not quite done watch it closely for 1-2 more minutes. If it is not crispy enough remove the foil and cook for 1 additional minutes.
Green bean tater tot casserole in a red baking dish with a wooden spoon.
Tater Tot Casserole with Green Beans & Ground Beef

Reheat casseroles with a cheese topping

It can also be challenging to reheat with cheese topping as it can easily overcook and become hard. Cheese reheating process:

  1. Oven method: Preheat your oven to 350°F (175°C). Cover the casserole with foil and bake for 20-25 minutes. Remove the foil and bake for an additional 5-10 minutes, or until the cheese is golden brown and melted.
  2. Microwave method: Place the casserole on a microwave-safe dish and cover it with a microwave-safe lid or microwave-safe plastic wrap. Microwave on high for 2-3 minutes, or until heated through. If you sprinkle a bit of extra cheese on top cook for 30 seconds to 1 minute longer to melt.
  3. Skillet method: Cut the casserole into individual portions and place them in a non-stick skillet. Heat on medium heat, covered, for 7-10 minutes or until heated through. If you want to put extra cheese on top cook for 1-2 more minutes.
  4. Air Fryer method: Preheat air fryer to 350°F, wrap with foil cook for 3-5 minutes giving it a shake every 2 minutes, for a crispier text remove the foil and cook for another 1 minutes, watching closely the cheese does not burn.

Tip: You can use cooking spray on the foil that is going to be against the cheese to help it not to stick the to cheese while cooking!

If you feel your cheese casserole is dry you can add water, extra cheese or even some milk in a Mac n Cheese to help bring back some moisture.

Cheesy Mac and cheese casserole in a white baking dish with a green and white napkin on the side.
Creamy Mac & Cheese Casserole

Frequently asked questions

How to keep a casserole warm

If you need to keep a casserole warm for a family gathering or for a longer time such as a party, here are some steps to help out:

  • Cover with a foil
  • Use an insulated carrier to transport a casserole for potluck
  • Keep warm in the oven at 200°F check for drying out
  • Use a slow cooker set to a warm setting

How to reheat a casserole from the fridge

Allow your refrigerated casserole to sit at room temperature for 30 to 60 min before cooking to avoid temperature shock of your dish. Cook at 350°F for a cooking time of 20-30 minutes.

Storing a casserole

Storing casserole leftovers in different ways:

  • Step 1: allow cooked casserole to cool at room temperature
  • Step 2: place in an airtight container, or use plastic wrap and foil
  • Eat within 3-4 days

How many times can you reheat a casserole

You can only reheat a casserole the 1 time, but the good news is it is best to freeze a smaller portion size to enjoy as needed leftovers for another day.

Can you freeze a casserole

You can freeze homemade casseroles or store-bought casserole in various ways as long as it is the proper way for future meals.

The best method is to use a freezer-safe container with a lid.

You can also use freezer proof zipper top bags. The best way is to wrap the right size in foil then placing in the zipper bags.

You can freeze a meat casseroles like a beef casserole, pasta casseroles or vegetable casseroles prepared the right way for quite a long time, 2-3 months.

How to thaw a frozen casserole

The best ways to thaw a casserole in a frozen state is to place it in the fridge overnight for at least 8-10 hours to thaw evenly.

You can also defrost it in the microwave watching closely to not cook the edges.

This is an important part of cooking a frozen casserole to help it cook more evenly in less time and not to cause temperature shock to ruin your bake ware.

Baked ziti with meatballs in a blue and white baking dish.
Baked Ziti Casserole

How to reheat a frozen casserole

It is important to thaw your casserole slowly in the fridge overnight.

Once your casserole is thawed you can cook it as instructed above at 350°F for 20-30 minutes.

If you have forgotten to thaw your casserole in time as let’s face it we have all done that!

You can defrost portions in the microwave which is not always the best option to thaw it completely without cooking the edges of the casserole.

In a pinch for better results you can transfer the casserole to a room temperature oven-safe dish.

Cook at 325° F or lower temperature slowly for 30-45 minutes of heating covered in foil. You risk breaking or cracking your dish however.

Philly cheesesteak casserole in a white baking dish.
Philly Cheesesteak Casserole with Ground Beef

We recommend however when you forget to thaw it, defrosting it in the microwave to get it partially thawed (or even in a skillet on the stove) then transfer to a room temperature oven safe dish to cook slowly at 325°F.

It is important to allow enough time for the center of the casserole to cook. Check often after 30 minutes to see if it is hot throughout to avoid overcooking.

To wrap it up I hope I have provided a comprehensive guide to help make things easier for the best ways to reheat your casserole!

Please see also my best ways to reheat a green bean casserole and chicken casserole.

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