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Can you put an open bag of popcorn in the microwave?

Microwaving an open bag of popcorn is not recommended. However, there may be times when you want to reheat some leftover popcorn and you don’t have access to an air popper or other preferred popcorn reheating methods. In these cases, microwaving an open bag of popcorn can be done, but should be approached with caution.

Quick Answers

Here are quick answers to some common questions about microwaving open popcorn bags:

  • It’s not ideal, but possible if done carefully
  • Only microwave leftovers, not a brand new unpopped bag
  • Use lower power and shorter cooking times to avoid burning
  • Watch closely and stop early if popping slows or you smell burning
  • Cover loosely with a paper towel to prevent splatter
  • Don’t re-microwave bags multiple times as they can catch fire
  • Transferring to a microwave-safe bowl is safer than microwaving the bag

Why Microwaving Unpopped Bags is Risky

Microwave popcorn bags are designed to be microwaved closed. Inside the bag is the unpopped popcorn kernels along with oil and seasoning. As the microwave heats up the oil and kernels, the steam builds pressure in the enclosed space which causes the popcorn to pop. If you try to microwave an open bag of unpopped popcorn kernels, it won’t work well because there won’t be contained steam pressure to make the kernels pop.

Another risk of microwaving an open bag of unpopped popcorn is that the oil can get too hot and start to smoke or catch fire. Microwave popcorn bags are designed to control the oil temperature for even heating. Without the enclosed space, hot spots can develop and lead to burning.

Tips for Microwaving Leftover Popcorn

While microwaving unpopped popcorn bags is not recommended, you can carefully reheat leftovers in an open popcorn bag in the microwave. Here are some tips:

  • Use lower microwave power, around 50%. Full power can scorch the popcorn.
  • Microwave in short intervals, 15-30 seconds at a time. Check frequently.
  • Stop early if popping slows down or you smell burning.
  • Cover bowl loosely with a paper towel to prevent splatter.
  • Transfer to a microwave-safe bowl for safest results.
  • Don’t reheat the same bag more than once or twice.

Microwave Popcorn Safety Tips

To safely enjoy microwave popcorn, follow these general guidelines:

  • Follow package instructions carefully, especially time and power level.
  • Stop the microwave early if popping slows or you smell burning.
  • Don’t leave microwaved bags unattended.
  • Allow bags to cool before opening to avoid steam burns.
  • Lay bags flat on a heat-safe surface, don’t hold in your lap.
  • Keep microwave interior and vents clean of oil buildup.
  • Don’t microwave unpopped kernels or reheat bags repeatedly.

Other Ways to Reheat Leftover Popcorn

For best results, consider these alternative reheating methods:

  • Stovetop – Toss kernels in a small amount of oil over medium-low heat.
  • Oven – Spread in a single layer on a baking sheet at 300°F for 5 minutes.
  • Air popper – Use an air popper on low air flow setting.
  • Paper bag – Place in a brown paper bag in the microwave.

Nutritional Value of Popcorn

Popcorn can be a healthy snack option depending on preparation method. Here is the nutritional value per 100g:

Nutrient Amount
Calories 376
Protein 12.6g
Carbohydrates 63.3g
Fat 4.6g
Fiber 14.5g
Sodium 18mg

Air-popped popcorn without oil or butter is the healthiest preparation. Microwave popcorn can also be fairly healthy if using reduced fat versions and watching portion sizes.

Popcorn Varieties

There are several varieties of popcorn to consider:

Kernel Types

  • Butterfly – Common hull-less kernel good for stovetop or air popping.
  • Mushroom – Rounded hull-on kernel used for microwave popcorn.
  • Pearl – Smaller hull-less kernel known as premium popcorn.
  • Hulless – Hull-less as name describes, good snack popcorn.

Color Varieties

  • Yellow – Most common, has buttery flavor when popped.
  • White – Delicate flavor and crunch.
  • Red/Blue – Colorful popcorn for snacks or decor.
  • Black – Known as ‘zebra’ for black & white specks.


  • Kettle corn – Sweet with mix of sugar and salt.
  • Caramel – Coated in sweet, sticky caramel.
  • Cheddar – Sharp cheddar cheese powder flavoring.
  • Jalapeño – Spicy kick from jalapeño powder.

Making Great Popcorn

For best results popping your own popcorn, follow these tips:

  • Use fresh, high-quality popcorn kernels.
  • Try different kernel sizes and types.
  • Coat with small amount of heart-healthy oil like canola or olive oil.
  • For stovetop, use a heavy pot with lid. Shake frequently.
  • For air popping, keep lid closed and don’t overfill.
  • Season while hot to stick. Try spices, herbs, Parmesan cheese.
  • Avoid burning for better flavor. Listen for popping to slow.
  • Allow to cool slightly before eating to avoid burns.

Storing Popcorn

To maintain freshness and flavor of popcorn kernels, follow these storage tips:

  • Store unpopped popcorn in an airtight container in cool, dark place.
  • Glass jars or resealable plastic bags work well.
  • Keeps up to 1 year at room temperature, 2 years refrigerated.
  • Freezing extends shelf life significantly to 2+ years.
  • Once popcorn is popped, eat within a few days for best freshness and texture.
  • Refrigerate or freeze popped popcorn in airtight bags or containers.

History of Popcorn

Popcorn has a long and interesting history:

  • Grown and eaten for thousands of years starting in Central America.
  • One of the oldest forms of corn, domesticated around 6,000 BC.
  • Discovered in ancient Peruvian tombs dating back to 4700 BC.
  • Aztecs had religious ceremonies centered around popcorn.
  • First introduced to colonists in 1612 by Native Americans.
  • Popularity spread in 1890s with street vendors using steam power.
  • First use of microwave popcorn bags in 1981 revolutionized preparation.
  • Americans consume over 17 billion quarts of popped popcorn annually!

Popcorn Science & Origins

Popcorn pops due to a unique scientific property of the kernel:

  • Has hard outer shell (pericarp) surrounding starchy interior.
  • Contains only 14% moisture compared to most corn’s 30%.
  • As kernel heats, water expands creating pressure inside.
  • Eventually the hull ruptures from internal pressure, allowing steam to escape and kernel to pop.
  • Believed to result from a genetic mutation of regular corn varieties.
  • Cross-breeding further optimized the trait over centuries.

This natural popping ability gives popcorn its fun snack appeal!

Popcorn Trivia & Fun Facts

Popcorn is full of surprising history and fun facts:

  • Illinois produces the most popcorn of any state.
  • There is an annual Popcorn Festival held in Valparaiso, Indiana.
  • During WWII, sugar rations made popcorn a popular treat.
  • Most popcorn comes from specially cultivated varieties, not field corn.
  • Popcorn needs between 10-20% moisture to pop optimally.
  • Popcorn sales significantly increase during times of economic recession.
  • The world’s largest popcorn ball weighed over 900 pounds!
  • National Popcorn Day is January 19.


Microwaving open popcorn bags comes with risks of burning, fire, and poor results. For leftover or stale popcorn, use lower power and short cooking times and watch closely to avoid overcooking. For freshest flavor and best experience, popcorn is best popped stovetop or with an air popper using quality kernels and seasonings.

With its uniquely popping property, long history, and reputation as a beloved snack, popcorn will continue to be a favorite food for enjoying at home or at the movies!