Ordering a piping hot pizza for delivery is one of life’s great pleasures. But let’s face it – leftovers are inevitable. Heating up those leftovers is convenient, but can you microwave a pizza box?
The short answer is yes, you can microwave a pizza box, but only if it’s labeled as microwave safe. Even then, it’s best to limit microwave time to 1 minute or less and monitor it closely. For longer reheating, transfer the pizza to a microwave-safe plate or container.
Keep reading to learn more about the do’s and don’ts of microwaving pizza boxes, as well as tips for safely reheating leftover pizza.
Why Microwaving Cardboard is Tricky
Pizza boxes are often made from cardboard or paperboard. This material is designed to be disposable and keep food warm temporarily. It’s not intended for extensive microwave use.
The main risks of microwaving plain cardboard are:
- Fire Hazard – Cardboard can catch fire if it overheats. Microwaves dry out paper materials, making them more flammable.
- Chemical Leaching – Adhesives, dyes and coatings on cardboard can leach chemicals into food when heated.
- Damage to Microwave – Arcing and sparking can occur if metal is hidden in the cardboard, damaging your appliance.
However, many modern pizza boxes are designed with microwave safety in mind. Let’s look at how to identify boxes that you can microwave.
Checking if a Pizza Box is Microwave-Safe
The safest bet is to look for explicit microwave instructions on the box. If there is no microwave-safe logo, check the cardboard closely for:
- A manufacturer’s label stating microwave-safe or ovenable
- Lack of any plastic, metal, or wax linings
- No adhesive, staples or magnetic closures
- Ink printing only on the outside, not touching food
Plain kraft paper board without dyes, coatings, or prints is generally safe to microwave briefly. But when in doubt, don’t microwave the box.
Microwaving a Pizza Box Safely
If you’ve determined your pizza box is microwave-safe, here are some tips to heat it safely:
- Limit heating time to 1 minute or less. Check and rotate the box every 30 seconds.
- Use lower power, around 50% or less. This prevents overheating.
- Leave pizza in the box and keep it a few inches from walls. Food absorbs energy instead of just the cardboard.
- Watch carefully so you can stop if any smoking or sparking occurs. Don’t leave the room.
- Line with a paper towel to prevent oil absorption which speeds heating.
Again, for longer reheating needs, transfer the pizza to a true microwave-safe container.
What About Pizza Hut, Domino’s, Papa John’s and Other Boxes?
Many national pizza chains design boxes safe for short microwave use. Here are some examples:
Pizza Hut Box
- Microwave-safe for 1-2 minutes max
- Plain kraft paperboard, FDA-approved for high heat
- Do not use if oil-stained
Domino’s Box
- Can be microwaved up to 1 minute
- Free of chemical coatings
- Check box closely for any plastic or metallic parts before heating
Papa John’s Box
- Labeled microwave-safe up to 1 minute
- Uses eco-friendly kraftboard with vegetable-based ink
Little Caesars Box
- Can be microwaved up to 1 minute
- Plain paperboard construction, no coatings
Of course, policies may vary between franchises, so verify microwave instructions are present before heating any box.
Microwave Power Settings
Using lower microwave power settings are safer when heating pizza boxes, takeout containers or other paper materials. This prevents overheating.
Here are some common microwave wattage and power settings to use:
| Power Level | Percent | Wattage* | Use |
|---|---|---|---|
| High | 100% | 1000-1200W | Boiling water |
| 7 or Medium-High | 70% | 700-840W | Gentle cooking, reheating foods with high water content |
| 6 or Medium | 60% | 600-720W | Cooking sensitive foods, thawing meat |
| 5 or Medium-Low | 50% | 500-600W | Simmering stews, heating pizza boxes |
| 4 or Low | 40% | 400-480W | Softening butter, warming baked goods |
| 3 or Defrost | 30% | 300-360W | Thawing bread, defrosting casseroles |
| 2 or Low-Low | 20% | 200-240W | Softening ice cream, raising yeast dough |
| 1 or Lowest | 10% | 100-120W | Keeping food warm, drying herbs |
*Wattages are approximate ranges for standard microwave ovens. Check manufacturer guide for your exact wattage.
As you can see, a lower power around 50%/500W is ideal for gently heating pizza boxes without overdoing it.
Microwaving Other Paperboard Containers
The same safety principles apply when microwaving other takeout containers or food packages containing cardboard or paperboard.
Examples include:
- Chinese takeout containers (without metal handles or staples)
- Paper soup cups or bowls
- Uncoated paper plates
- Plain paper cups (no plastic lids or wraps)
- Kraft paper deli sandwich wrappers
- Cardboard wraps on burritos or sandwiches
Stick to short 1 minute or less heating times. And transfer food out if cooking longer, adding steam, or if paper item seems overly dry.
Never microwave cardboard with:
- Metal (like staples or foil) which can spark
- Plastic linings that can melt or leach chemicals
- Adhesives that contain harmful compounds when heated
Microwaving Pizza: Better Reheating Methods
While microwaving the pizza box is quick, you can get more delicious results using these other reheating methods:
- Conventional Oven – Place pizza slices on a baking sheet at 400°F for 6-8 minutes until hot and crispy.
- Toaster Oven – Slice pizza and toast 4 minutes at 350°F for a nice crunch.
- Skillet – Place pizza in a skillet over medium-low heat for a crisped crust.
- Microwave – Put slices on a microwave-safe plate, bowl or pizza crisper. Heat 1-2 minutes based on thickness.
- Stir Frying – To revive dried out pizza, slice or dice it and stir fry in oil for a quick pizza fried rice.
Properly storing the leftovers also helps preserve that fresh-baked pizza taste and texture for several days.
Storing Leftover Pizza
Pizza leftovers should be refrigerated within 2 hours. Follow these storage tips:
- Let pizza cool completely before boxing up.
- Transfer slices to sealable plastic bags or airtight containers. Avoid wrapping in foil.
- If keeping the whole pie, tent it lightly with foil to prevent drying out.
- Refrigerate for 3-4 days maximum. The dough will get rubbery after that.
- For longer storage, freeze pizza up to 2-3 months. Thaw overnight in the fridge before eating.
- Reheat using the oven or toaster oven for the best quality. Microwave only if needed.
With proper reheating and storage methods, you can stretch that tasty pizza for several meals.
Frequently Asked Questions About Microwaving Pizza Boxes
Can you microwave any pizza box?
No. Only microwave if the box is specifically labeled as microwave-safe. Many pizza boxes contain coatings, inks or liners that can be unsafe when heated. When in doubt, transfer pizza to a plate or dish before microwaving.
How long can you microwave a pizza box?
Limit microwave time to 1 minute or less. Check frequently and stop if you see smoking or sparking. Transfer food to a microwave-safe container if you need to heat longer than 1 minute.
Does microwaving a pizza box cause cancer?
As long as the cardboard is labeled microwave safe and you follow proper precautions, microwaving briefly does not cause cancer. Some inks and chemicals could leach into food if you microwave an unsuitable box.
Can you microwave a frozen pizza in the box?
No, don’t microwave frozen pizzas still in the box. The cardboard and plastic top will likely contain materials unsafe for microwaving. Remove frozen pizza and microwave on a safe dish per package instructions.
Does grease on the pizza box matter?
Yes, grease stains can make the cardboard heat rapidly and risk fire. Use paper towels to blot any oil before microwaving. Limit heating time and monitor closely.
The Bottom Line
Microwaving those pizza leftovers in the box is convenient, but has some safety concerns. With care, plain kraft paperboard boxes can be suitable for very brief 1 minute reheating. But for frequent pizza warming needs, your best bet is transferring slices to true microwave-safe containers.
Focus on the joy of pizza, not the headaches of cleaning burnt cardboard out of your microwave! With smart storage and reheating methods, you can continue enjoying every last bite.
