How to Reheat White Castle Burgers

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If you’ve ever eaten at White Castle before, you know how amazing their burgers are. These mini-sized hamburgers are incredibly addicting. Imagine it’s the day after, and you want to reheat your leftover White Castle burgers. Can you? Yes, White Castle burgers are safe to be reheated.

If you want to reheat White Castle burgers and make these mini burgers taste like you just got them from the restaurant, you’re in the right place. Find out how to reheat White Castle burgers below.

Related article – How to Reheat Philly Cheesesteak.

Facts About White Castle Burgers

Founded in 1921, White Castle is a beloved part of the American fast food scene as it’s the first hamburger chain in the USA. They grew across the mid-west and east coast, and now there are hundreds of their restaurants in the US.

Their White Castle burgers are famous for their unique, petite size, oniony taste, and affordable price. Their unique cooking method made White Castle Burgers so popular. A pile of onions is placed on a grill, and the slider-sized beef patties are placed on top. Then, the steaming process begins, hence the delicious onion taste that makes White Castle burgers so delicious!

Have you ever wondered why there are 5 holes in the beef patty?

The reason why there are holes in the beef patty is because of the steaming process. 

The patties cook well and quickly as the hot steam escapes through the holes in the meat, leaving a distinct onion flavor and aroma. 

How to Reheat Frozen White Castle Burgers in the Microwave

The best way is to reheat them while the bread is still soft. Make sure you take off the lettuce and tomato before reheating these.

  • Get a microwave-safe plate
  • Remove the burgers from the plastic
  • Put them upside down into a couple of paper towels
  • Roll the paper towel around the burgers and tuck both ends 
  • Put the burgers on the plate upside down (so that the bottom bun is facing up)
  • Microwave on high for 40 secs
  • After microwaving, flip the burgers over and tuck the paper towels under them (again)
  • Microwave on high for 40 secs

How to Reheat Frozen White Castle Burgers on the Stove Top

If you have leftover frozen White Castle burgers and want them to taste fresh and juicy, then follow the instructions below: 

  • Cover the bottom of a medium saucepan with water
  • Keep the water below the bottom of the insert
  • Cover and bring to a boil
  • Cover the insert with foil, so bun heels do not come in contact with the insert
  • Put the buns upside down
  • Cover and reduce the heat
  • Steam for 10-12 minutes if frozen, 8-10 minutes if thawed, or until the center of the sliders reach 165 degrees F
  • Remove burgers from the pan using a spatula

How to Reheat White Castle Burgers in the Oven 

If you want to warm up previously fresh White Castle burgers in the oven while maintaining their flavor you need to:

  • Preheat the oven to 350°F
  • Remove the slice of pickle from the burgers
  • Using a broiler pan, heat some water and pour this into the tray
  • Place the white castle burgers on top of the boiler tray 
  • Place the aluminum foil above the burgers 
  • Leave the White Castle burgers in the oven for 10-12 minutes
  • Remove the tray from the oven and reassemble the burgers (put back the pickles, lettuce, and tomatoes).

If the White Castle burgers are frozen, add 2-3 minutes to the cooking time.

How to Reheat White Castle Burgers in the Air Fryer

If you want to air fry frozen White Castle burgers:

  • Place the white castle burgers (upside down) in the basket of the air fryer
  • Set the air fryer to 390°F for 10 minutes
  • After 5 minutes, flip the burgers over

To reheat White Castle burgers that are fresh:

  • Remove the top bun and place the burgers in the air fryer basket
  • Cook for about 5 minutes at 320°F
  • Add the top bun and cook for extra 30-40 seconds
  • Rebuild the burger and add the condiments 

How to Reheat Frozen White Castle Burgers in the Instant Pot 

Instant pot is a perfect way to reheat White Castle sliders, as originally they’re supposed to be steamed, and an instant pot is perfect for steaming.

  • Place the trivet in the instant pot
  • Add a cup of water 
  • Trim and add aluminum foil on top to prevent the burgers from touching the water and becoming soggy
  • Place the burgers on top of the foil
  • Close the lid and set the valve into a ceiling position
  • Set instant pot to 3 minutes in high pressure
  • Quick release the steam and open the instant pot lid

How to Preserve the Texture and Flavor of White Castle Burgers While Reheating

It’s important to keep in mind that the White Castle burgers may be incredibly juicy. However, they have onion, sauce, and juices from the meat, so they can’t be kept outside the fridge without spoiling. Also, when it comes to tomatoes and lettuce, they have a tendency to get spoiled during storage, so it’s better to throw them away.

For the burger buns, you can toast them separately. This will help preserve the bread’s texture. Simply pop the buns in the toaster oven for a few minutes.

You can store White Castle burgers in the fridge; however, if you haven’t eaten them by the 4th day, they should be thrown out. Additionally, you can also freeze the White Castle burgers; just place the leftovers in an airtight container or plastic wrap and store them in the freezer for up to 3 months. 

How to Recognize When White Castle Burgers are Heated to the Desired Temperature

Whatever method you’re using to reheat the burgers, make sure that the meat has an internal temperature of 165°F. 

Nutritional Value

One White Castle Bun has 140 calories.  


Potential health benefits and concerns

One white castle bun contains 140 calories, which is about 7% of the daily 2,000 caloric intake. However, despite the low calories in a bun, a white castle burger is high in fat as it contains 7g per burger (2.5g saturated fat). Saturated fats can have negative effects on cholesterol levels so less than 7% of total calories should be from saturated fats. 


A White Castle burger contains ground beef, onion, salt, water,  dill pickle slices, beef bouillon, and dinner rolls. All of these ingredients are safe to reheat by following one of the multiple methods discussed in this article.

In more detail, according to White Castle’s official website:

Enriched Bleached Wheat Flour (Wheat Flour, Malted Barley Flour, Niacin, Iron, Thiamine Mononitrate, Riboflavin, Folic Acid), Water, Sugar, Soybean Oil, Contains 2% Or Less Of Each Of The Following: Yeast, Salt, Vital Wheat Gluten, Calcium Stearoyl Lactylate (Csl), Guar Gum, Monoglycerides, Monocalcium Phosphate, Sodium Alginate, Ascorbic Acid ((Vitamin C), Enzymes. CONTAINS: WHEAT

Is It Safe to Reheat White Castle Burgers More Than Once?

According to the Food Standards Agency, you can safely reheat these burger patties multiple times; however, it is recommended to do so only once. 


White Castle sliders are good for a quick snack. If you follow the tips in this article, you aren’t running the risk of changing the taste and texture of a White Castle burger patty too much. Hopefully, you now know how to reheat leftover burgers from White Castle.

If you love cooking steak, but you’re not sure which oil is the best to use, check out this article.

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