The Best Ways to Reheat Green Bean Casserole

These are the best ways to reheat green bean casserole with the best overall, the fastest, and three honorable mention reheating methods for your holiday leftovers.

Best: Oven Fastest: Microwave Runners Up: Air Fryer, Stovetop, Crockpot

The holidays have come and they’ve almost gone, and we’ve fully enjoyed ourselves by cooking up a wide variety of traditional favorites. Let’s be honest, it wouldn’t be the holidays without side dishes like corn casserole, green bean casserole, sweet potato pie, and cranberry sauce showing up next to the main dish at potluck dinners and get-togethers.

But with all that cooking, we knew we would end up with leftovers. So, how do you reheat the classics that were so good when they just popped out of the oven? This is the question we set out to answer, and answer we have!

Below, you’ll find five ways to reheat green bean casserole, including the best overall method, the fastest method, and three other methods we’ve found to work pretty well. Not all will produce a reheated casserole that is fit to serve guests, but they’ll all do a good enough job to give you a second or third night with leftovers you’ll enjoy. These methods work for our favorite recipe that uses fresh green beans and real cheese, but they also work for the classic green bean casserole that uses canned green beans with canned creamy mushroom sauce.

Note: Reheating time can vary depending on the portion size and whether fresh ingredients are used, among other factors. The times listed below should be used as a general guideline.

Jump Ahead:

Is It Safe to Reheat Green Bean Casserole?

First of all, is it safe to reheat green bean casserole? The simple answer is: almost always, yes. But there is a caveat. It is safe to reheat if the casserole hadn’t been left out for too long. Green bean casserole has milk products, and some recipe variations have meat, as well. Because of this, the casserole shouldn’t be outside of a refrigerated environment for more than 2-3 hours.

So, if your casserole sat out on your counter from Thanksgiving lunch until you went to bed for the night, it’s probably not the wisest idea to try and reheat that casserole. You’ll, unfortunately, need to say a fond farewell to your delicious side dish rather than risking it and reheating potentially spoiled milk and meat products.

On the other hand, if you only had the casserole out for Thanksgiving dinner or Christmas lunch, then it went right into the refrigerator until you pulled it out to reheat, you’re good to go. You can safely reheat your beloved side dish and enjoy it for yet another lunch or dinner.

So, is it safe? Only if the dish wasn’t left out at room temperature for more than a couple of hours. If in doubt, don’t do it. You may have to throw some leftovers away, but at least you won’t get a side of food poisoning along with your after-Christmas dinner.

The Best Way to Reheat Green Bean Casserole: Oven

green bean casserole cooked in crockpot

Moving on! Now that you’ve determined you can reheat that delicioso leftover casserole, what’s the best method? We’ve found five ways, but one method is the clear winner: Oven! We know, we know – you probably baked the casserole in the oven in the first place, should you really reheat it that way, too?

Yes, most definitely, and here’s why. The oven is excellent at heating dishes evenly without drying them out or making them mushy. Other reheating methods can tend to either dry out the casserole or cook it down too much. When using the oven, however, the dish heats evenly, and you can even put toppings on top to crisp up or melt. The oven method gave us the best results, hands down.

To reheat the green bean casserole in the oven, you’ll want to:

  • Preheat the oven to 350 degrees Fahrenheit.
  • Transfer the casserole from your airtight container to an oven-safe casserole dish.
  • Once the oven preheats, place the baking dish into the oven and heat for 15-20 minutes, or until heated through.
  • If adding fresh toppings, add in the beginning, then cover with aluminum foil if the top darkens too quickly. Aim for golden brown and no darker.

Voila! Reheated green bean casserole that looks and tastes amazing!

The Fastest Way to Reheat Green Bean Casserole: Microwave

We get it, we don’t all have time to wait for 20-30 minutes for a casserole to reheat. Maybe you just want an easy way to heat up a single-serve portion because your casserole is so stinkin’ good you want to eat it for breakfast and lunch the next day. If that’s you, then you’ll want something fast, even if the final product doesn’t look super pretty.

And now for the fastest way to reheat that delicious side dish: microwave! Microwave isn’t our “best” overall method for reheating because it can tend to make the casserole a bit soggy and overcooked, so it won’t look spectacular, even though the taste will be spot-on. However, if you need a quick warm-up for yourself and your family for a meal of leftovers, you can’t beat how fast a microwave will handle the job.

To reheat your green bean casserole in the microwave, follow these simple steps:

  • Transfer the casserole to a microwave-safe bowl or dish. If it’s already in a microwave-safe dish, be sure to remove any plastic wrap or foil if used.
  • Microwave on high, starting with 5 minutes for two servings. Continue to microwave incrementally for 3-5 minutes until the casserole is warmed through.
  • Add some extra parmesan cheese or crispy french onions to spruce up the dish when reheating.

Sprinkle additional fresh toppings or even more cheese when plating to help your leftover green bean casserole look its best.

Three More Reheating Methods for Green Bean Casserole

Though the first two reheating methods are the best and fastest, there are three more heating methods that absolutely deserve an honorable mention. They are air frying, stovetop, and slow cooker. Let’s look at each.

Air frying

Air frying does an amazing job at heating food up quickly. The only potential downside to using an air fryer to heat your casserole is that it can tend to dry items out just a little too much. If your casserole is already pretty wet, then an air fryer can help balance it by pulling out some moisture. But if the casserole is already on the dry side, then you might want a use a different reheating method.

To reheat by air frying:

  • Preheat the air fryer to 350 degrees F
  • Form a foil dish and place the casserole portion into the foil.
  • Heat for 5 minutes, then check. Continue reheating at 3-5 minute intervals until warmed through.

Add fresh crispy onions or cheese to freshen up the presentation prior to plating this holiday favorite.


Stovetop is one of the messier reheating options, simply because you’re typically dumping the casserole into a pan or pot to reheat it. It likely won’t “look” pretty after it’s reheated, but don’t let that stop you!

To reheat your green bean casserole on the stovetop, you’ll want to:

  • Add a small amount of oil to the bottom of your pan or large skillet if it’s stainless steel.
  • Place the casserole into the pan, and set it over low heat.
  • Stir occasionally to make sure the bottom of the casserole doesn’t burn.
  • Remove when fully heated through.

Because the casserole was stirred during the reheating process, it probably doesn’t look super pretty. We don’t recommend using this method for reheating if you’re serving guests. However, if you are and you need to freshen it up, you can always add some extra toppings and place it under the broiler for a few minutes to crisp up the top or melt some cheese.

Slow cooker

The final reheating method that deserves an honorable mention is the slow cooker. Now, this clearly won’t work for everyone, but if you have a large amount of casserole left and you want to set it and forget it, the slow cooker can come in handy.

To reheat green bean casserole in the slow cooker:

  • Add a bit of oil if using a ceramic crock to prevent sticking.
  • Turn the crockpot to ‘high heat.’
  • Heat for 30 minutes to 1 hour.

Sprinkle some fresh crispy fried onions or grated cheese on top and let melt before placing it on the dinner table.

Tips and Tricks for Reheating Green Bean Casserole

I have a frozen casserole. Is there a right way to reheat it?

Thaw the green bean casserole in the refrigerator first. When fully thawed, choose one of the methods above. If cooking the whole casserole for the first time, follow the original recipe for heating time.

Should you reheat a casserole uncovered or covered?

Either method is acceptable. The big difference in deciding which to choose comes down to whether your casserole is on the wet or dry side. Dry casseroles should be reheated covered, so they don’t dry out more. If the casserole is pretty wet, however, you can reheat it uncovered to help dry out some of that moisture.

My green bean casserole sat out all day. Can I still reheat it?

Unfortunately, no. There is a fine safety line for products with dairy in the ingredients, like cream of mushroom soup. If the casserole sat out of refrigeration for longer than 3 or 4 hours, you’re risking food poisoning, even if you reheat it.

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