Name: How To Reheat Breakfast Casserole
Cook time: 15 min
Total time: 15 min
Ingredients: 1 portion breakfast casserole; 1 portion butter or cooking spray

Table of Contents

When it comes to reheating eggs, it can be tricky to get the right balance.

Too little heat and you’ll end up with a watery, sloppy mess.

Too much heat and you’ll end up with a tough, rubbery dish that barely resembles an egg casserole.

In this article, I test several different ways of reheating breakfast casserole to see which one gives the fluffiest egg with the least effort.

In a rush? Here’s the short answer.

The best way to reheat breakfast casserole is in the skillet. Lightly butter a pan and heat it on medium heat. Once hot, add your slice of casserole and fry it on both sides for 1-2 minutes until lightly browned. For a whole breakfast casserole, the oven works best.

A note on my experiment

I made a big batch of egg casserole on Sunday morning and stored it in the fridge overnight.

The following day, I tested reheating egg casserole:

In the oven
In the microwave
In the skillet
In the air fryer
In the toaster

Reheating the egg casserole in the skillet turned out to be my favorite method because of the crispiness I could get on the outside of the egg.

Reheating in the oven was also a great way to make the casserole feel fresh, but it can take a long time.

Using the microwave is a bit risky.

While it can get the job done, it might be touch and go as far as texture is concerned.

Finally, the air fryer is good for smaller slices but is at risk of drying out your breakfast casserole if not closely monitored.

Reheating breakfast casserole in the oven

To reheat a slice of breakfast casserole in the oven, preheat the oven to 350°F (180°C), cover with foil, and heat for around 10 minutes (less in a toaster oven). For an entire dish, let the casserole come to room temperature first and reheat it, covered, for 20 to 30 minutes in a conventional oven.

How to reheat breakfast casserole in the oven:

Preheat the oven to 350°F (180°C).
Remove the breakfast casserole from the fridge and let it come to room temperature (skip this step if just heating a slice).
Cover the breakfast casserole with foil and heat a slice for 5-10 minutes, or heat a whole casserole for 20-30 minutes.
To crisp the top, remove the foil for the last few minutes of heating.

A quick way to test if your breakfast casserole is hot all the way through is to use the knife trick.

Stick a sharp knife into the egg and feel the metal when you pull it out.

If the metal is warm, the casserole is heated through.

Covering the dish with foil will prevent the egg from drying out, but to take your breakfast to the next level, remove the foil near the end and sprinkle some cheese over the top.

Trust me. It’s Delicious.

My verdict

My breakfast casserole came out of the oven tasting great – it was pretty much indistinguishable from the fresh version.

The only real downside is how long it takes (although this is less of a concern if you have a toaster oven).

The oven is your only real option if you have a whole breakfast casserole to reheat.

Reheating breakfast casserole in the microwave

To reheat breakfast casserole in the microwave, put a slice of your casserole in a microwave-safe dish, then cover the top with a damp paper towel. Heat on 50% power in 30-second intervals until heated through.

How to reheat breakfast casserole in the microwave:

Put a slice of breakfast casserole on a microwave-safe plate.
Cover your dish with a wet paper towel.
Heat on 50% power in 30-second intervals until heated through.

Heating on a lower power and using short time intervals helps prevent overcooking the eggs.

One thing I noticed was that the watery vegetables didn’t fare very well in the microwave – they leaked moisture and left the casserole a bit soggy.

Personally, I would avoid the microwave if you have lots of water-logged veg in your casserole.

But if you can’t, line the plate with a dry paper towel to help soak up the excess moisture.

My verdict

The microwave worked okay for me, but I was very careful not to overheat the egg.

It’s super quick and convenient, which helps outweigh the risk of rubbery eggs.

Reheating egg casserole in the skillet

To reheat egg casserole in the skillet, melt some butter or heat some oil over medium heat. Add a slice of the casserole to the pan and heat for 2-3 minutes. Flip, then heat for two more minutes, repeating as needed.

How to reheat egg casserole in the skillet:

Melt butter or heat oil in a skillet over medium heat.
Place a slice of egg casserole in the pan and heat for 2 to 3 minutes, checking it’s not over-browning. If it’s heating too quickly, turn the heat down.
Flip, then heat for 2 more minutes.
Repeat as needed until heated through.

If you’re using a non-stick pan, there’s no need to add butter or oil (but I still like to use butter for extra flavor).

Stick to a medium heat until the egg casserole is hot in the middle.

Then, if you want to add some extra crispiness to the outside, you can turn the heat up to high for a minute or two.

My verdict

This was my favorite method.

The egg casserole was moist and fluffy on the inside, with nice crisp edges, and the butter really complemented the flavors of the casserole.

The only downside was having a pan to wash up afterward!

Reheating egg casserole in the air fryer

To reheat egg casserole in the air fryer, heat your unit to 300°F (150°C). If you want to crisp the outside of the egg, brush it with melted butter or spray it with some cooking spray. Place your slice of casserole in the air fryer and heat for 3 to 4 minutes.

How to reheat egg casserole in the air fryer:

Heat your air fryer to 300°F (150°C).
Brush a slice of egg casserole with butter or spray with oil for crisp edges.
Place your slices in the air fryer, keeping them to a single layer.
Heat for 3 to 4 minutes or until heated through.

If you’re worried about your breakfast casserole drying out, wrap it in foil.

However, it’s heating for such a short period of time, and drying out isn’t too much of a danger.

One of the air fryers’ limitations is space.

Allow for plenty of air circulation around your slice of casserole to ensure effective heating.

My verdict

The air fryer is a good, quick method for smaller slices.

But I found with a thicker slice, the outside dried out before the middle was hot.

It’s a fine line between a crispy edge and an overcooked egg.

Reheatingegg casserole in a toaster

To reheat youregg casserole in a toaster, make a makeshift toastie pocket using a cut piece of parchment paper (or use an actual toastie pocket). Wrap the parchment paper around a slice of egg casserole and gently place it in the toaster. Reheating your casserole in this way will take 1-2 minutes.

This is a really quick and easy method, as long as your egg casserole slices aren’t too thick.

Why didn’t anyone think of this sooner?!

How to store egg casserole

To store egg casserole, cut it into slices and let cool it to room temperature. Place the slices in an airtight container lined with a paper towel. If you need more than one layer, separate the layers with parchment paper. Keep the egg casserole in the fridge for 3-4 days.

The paper towel in the bottom of the container will absorb any moisture that might leak out and make your casserole soggy.

If you don’t want to separate the casserole into slices first, simply wrap the whole thing in plastic wrap or foil.

You can also wrap individual slices in plastic wrap if you want – this will make it super easy to grab one and head out the door to work.

Can you freeze egg casserole?

Egg casserole freezes well. The dish freezes best when there aren’t a lot of watery vegetables in it. Stick to meats, cheese, potatoes, and more sturdy vegetables like sweetcorn or peppers. If you’re prepping in advance, undercook your eggs slightly to prevent overcooking when you reheat the casserole.

How to freeze egg casserole:

Cool the egg casserole to room temperature.
Slice for storing individually or leave it whole.
Flash freeze the slices by putting them in a single layer on a parchment-paper-lined baking sheet and freezing them uncovered for one hour.
Once frozen solid, put the slices in a freezer bag and remove as much of the air as possible (I suck it out with a straw, or you can dunk the open bag in a bowl of water to force the air out). This helps avoid freezer burn.
If freezing a whole casserole, wrap the dish in a layer of plastic wrap, then in foil.
Store for up to 2 months.

Flash freezing will prevent the slices from sticking together in the freezer bag.

If you don’t want to flash freeze them, just separate the layers with parchment paper.

Make sure you’ve cooled the egg casserole to room temperature before freezing.

Putting a hot egg casserole in the freezer will lead to ice crystals forming in the egg and ruin the texture.

If you want to freeze a whole casserole, I recommend freezing it in a foil baking dish. Then you can easily transfer it straight from the freezer to the oven.

How to reheat frozen egg casserole

You can reheat egg casserole straight from frozen in the oven. Preheat the oven to 350 and wrap the casserole in foil. Heat for 20 minutes for a slice or 40-60 minutes for a whole casserole. You can also blast the egg casserole in the microwave for 2-3 minutes, but you risk ending up with rubbery eggs.

Alternatively, thaw the egg casserole in the fridge overnight. Then reheat it using any of the options above.