7 Foods and Drinks You Should Never Microwave

We adore our air fryers, Instant Pots, slow cookers, ovens, and grills. But if Team BHG had to choose just one kitchen appliance BFF for our busiest days, we’d have to select the microwave. It’s remarkably efficient, requires zero preheating or other gear (unlike the gas or charcoal you’ll need to get that grill going), and can actually be quite stylish, as our guide to the best microwaves prove.

Despite its speed and versatility, though, there are some things a microwave can’t do.

We tapped Sarah Brekke, M.S., Better Homes & Gardens Test Kitchen brand manager, to walk us through the consumable items that we should never microwave, whether because they pose a safety risk or simply due to the huge impact on quality.

Do not microwave:

1. Raw Hot Peppers

“These contain a compound called capsaicin, which is what makes them spicy. When heated, the capsaicin turns into vapor and these fumes can be quite irritating when inhaled or in contact with your eyes,” Brekke explains. If you need to cook hot peppers, say, you’re roasting them for a taco garnish or are trying to tame their bite a bit for salsa, be sure to sauté, roast, or grill the hot peppers in a well-ventilated area, Brekke says. (And be sure not to wash your hands well with soap and water after handling the hot peppers.)

2. Eggs in Their Shell

“Shel-on eggs, when microwaved, can explode due to the moisture inside being heated to the boiling point and steam building,” Brekke warns. Shell-on eggs should only be cooked in boiling water or using other tried-and-true methods for making hard- or soft-boiled eggs. Besides boiling, we swear by steaming and making boiled eggs in the Instant Pot or other pressure cooker.

3. Grapes

We adore them frozen, blended into smoothies, folded into sweet or savory salads, by the handful as a snack, and transformed into wine. But we don’t love grapes in the microwave. In fact, we never, ever place them there, because “grapes can spark when heated in the microwave,” Brekke says. The science behind this one is quite complex, and seems to be related to the way electromagnetic fields build up between the grapes. Whatever the actual reason, we keep grapes out of the microwave and instead cook them in a skillet or roast them in the oven if we aren’t serving fresh grapes in their raw form.

4. Breaded or Fried Leftovers

Air-fried, oven-fried, and deep-fried leftovers do not reheat well in the microwave, Brekke says. “The breading will lose all of its original crispness.” If you’re lucky enough to have extra Ranch Fried Chicken, Spicy Oven-Baked Fish and Sweet Potato Fries, Air-Fried Green Tomatoes, or other homemade or restaurant-crafted breaded delights, your best bet is to reheat them in the oven, on a wire rack set inside sheet pan, or air-fry the food to refresh that crispy coating.

5. Frozen Meat

The microwave can be utilized on a defrost setting to expedite the thawing of pieces of meat, Brekke confirms. But attempting to cook a piece of frozen protein completely in the microwave “will yield poor results,” she says. “Microwaves cook food from the inside out and to get the center of the meat cooked to a safe temperature will result in the exterior of the meat being tough, dry, and leathery.” If you want to cook a piece of meat that is frozen, our Test Kitchen experts recommend that you thaw it in the refrigerator (overnight often does the trick) or feel free to get things started with a short shift in the microwave, before finishing the cooking in a skillet, in the oven, or on the grill. If you’re hoping to cook the meat from frozen without thawing, turn to your Instant Pot, Brekke says, “This is a much better tool for cooking larger pieces of frozen protein.”

6. Alcoholic Beverages

A fair amount of boozy beverages are designed to be enjoyed warm: Hot Toddies, Mulled Wine, Hot Buttered Rum, Spiked Hot Chocolate, to name a few. Be careful as you prepare your spirited selection, Brekke advises. “Alcohol molecules are volatile and can ignite when exposed to the electromagnetic waves in the appliance. To heat an alcoholic beverage, we recommend using a saucepan on a stovetop.” Or try a slow cooker if your drink can hold up to longer simmer times.

7. Anything That's Expired

This one holds true regardless of the appliance. The USDA says that most leftovers can be refrigerated for 3 to 4 days, then should be discarded. As far as fresh fare goes, turn to this guide from FoodSafety.gov. Aim to use purchased packaged items by the “use by” date listed on the jar or bottle. (Keep in mind that there is often plenty of wiggle room with those “best by” and “use by” dates. Here's what experts say about eating food past its expiration date.)

Other Things You Should Never Microwave

It’s not just about the food and drink. Certain materials don’t play nicely with the appliance due to the way it uses very short, high-frequency radio waves to heat.

Meredith Carothers, food safety specialist for the USDA’s Food Safety and Inspection Service in Washington D.C., confirms that the following items are not safe to use in the microwave:

• Aluminum foil (there are some exceptions to this rule, which you can find here).
• Single-use plastic containers, such as butter tubs, whipped topping containers, and cottage cheese or yogurt cartons.
• Foam-insulated service ware, like cups, bowls, plates, or trays.
• Metal pans or metal twist ties.
• Newspapers.
• Paper bags.
• Table settings with metallic paint or trim.
• Takeout containers with metal handles or pieces.

If a container or package shows signs of melting at any point in the process, stop microwaving and discard what’s inside.

If you’re unsure if a utensil is safe to use in a microwave, the USDA recommends trying this test:

• Fill a glass measuring cup with 1 cup of tap water.
• Place the water in the microwave next to, but not touching, the utensil.
• Microwave on high for 1 minute.
• If the utensil feels warm or hot to the touch, it’s probably not microwave safe and likely contains metal in the material or glaze. Do not microwave this, as the item or bottom of the microwave might crack.

One final note about things not to microwave: " A microwave should never be run without anything inside it,” Brekke says. “If all of those micro waves have no food to absorb the energy, it will damage the appliance.”

Put your microwave to good use with our favorite recipes including Homemade Microwave Mac and Cheese, a 5-minute microwave chocolate cake, and an ultra-easy microwave peanut butter cup.