Can You Microwave Coffee in Styrofoam Cup? (Solved)

Categorized as Microwave Safety
can you microwave coffee in a styrofoam cup

It doesn’t matter if you’re a college student looking to save money on coffee or an office worker who needs their caffeine fix before they start their day – we all have those days where we don’t have time for our favorite mug of joe. When faced with this dilemma, many people turn to their microwave ovens to save the day. But is this safe or not?

Can You Microwave Coffee in a Styrofoam Cup?

You can microwave styrofoam cups of coffee, but with a few caveats.

  • First of all, avoid microwaving polystyrene containers that are not labeled microwave safe. You can usually find this label on the bottom of the cup.
  • Secondly, inspect the cup to make sure there are no cracks or other damage to the styrofoam. A damaged cup could cause your coffee to leak.
  • Thirdly, set the power level of your microwave oven to a medium setting. Some guides recommend setting the power level at 80%. However, this recommendation is only meant if you use glass or ceramic mugs. If you use a styrofoam container, you should use a lower power setting – between 30-50% to avoid the cup catching on fire.
  • And finally, nuke the coffee for only 30 – 45 seconds at a time. You do not want to keep the cup in the microwave for longer than a minute at a time, or you risk burning your coffee.

Once you’ve followed these simple guidelines, you’re ready to enjoy your microwaved coffee in a styrofoam cup.

Is It Safe to Microwave Styrofoam Coffee Cups?

Styrofoam is technically a trademark name for extruded polystyrene foam used to make insulation for homes or buildings.

Over the years, the term styrofoam has been colloquially used to refer to an expanded polystyrene foam used to manufacture disposable plastic food containers and take-out plastic containers, leading many people to incorrectly use these terms somewhat interchangeably.

What makes styrofoam or polystyrene containers so good at transporting food is the fact that they insulate extremely well, which makes them an excellent choice for those who want their food and beverages warm for as long as possible.

The FDA itself has determined for decades that styrofoam is safe for use in contact with food. This means you don’t have to worry about the chemicals leaching into your food.

In addition, they are lightweight and cheap to produce. All of these benefits make styrofoam containers a staple of take-out food chains everywhere.

However, it’s an entirely different story if we’re talking about microwaving polystyrene foam containers.

There is a common concern that microwaving polystyrene containers can release toxic chemicals into your food. Two of the most commonly cited compounds are styrene and benzene. Styrene is a chemical that has been linked to cancer in some studies, while benzene is a neurotoxin that can cause brain and nerve damage.

When you microwave polystyrene, the chemicals within the foam begin to break down and leach these potentially harmful chemicals into your food. This is why the traditional plastic and polystyrene containers are not meant to be reused for microwaving.

Luckily, there is a newer type of styrofoam container that is designed to be microwave safe. This particular styrofoam container has been tested and deemed able to withstand high temperatures and is not likely to produce dangerous chemicals when used in microwaves. The FDA and other organizations have all signed off on the safety of this new styrofoam product.

Safety Tips for Microwaving Coffee in a Styrofoam Cup

Ultimately, styrofoam cups were not meant to be microwaved. Although there is a newer type of styrofoam container that is microwave safe, it doesn’t mean there is no risk involved.

Keep that in mind while following these tips for microwaving coffee in a styrofoam cup:

  • Never reuse the same styrofoam cup for microwaving purposes. It is simply too risky, as the material can break down with heavy use and may cause you to ingest chemicals from the depths of your cup.
  • Check for any damage to the cup. If there is any sort of dent, blister, or crack, then do not microwave it, as this can cause the styrofoam to break down.
  • Be careful when adding sugar to your coffee, as the sugar will cause the liquid to foam and bubble.
  • Know your microwave. Some microwaves are far more powerful than others and can heat differently depending on their wattage.
  • Microwave your coffee in short bursts of around 30 seconds until it is heated to your liking. Overheating the cup can be harmful, so make sure you pay close attention and check on the cup frequently.

If you still have some questions about microwaving styrofoam, you may also want to read other articles that I’ve written on this subject:

How To Properly Reheat Coffee in the Microwave

Quite often, we forget the coffee we just brewed or the coffee we just bought from our favorite coffee shop. But before chucking it out and feel guilty for wasting it, remember that you can always reheat coffee in the microwave.

Here are some tips for doing so:

If you want to reheat your cold cup of joe in the microwave, the first thing you need to do is to transfer it to a microwave-safe container. Then, to reheat your coffee without burning it, you can simply adjust the power level on your microwave.

How do you know which power level is best for reheating your coffee? After placing your cup of coffee inside the microwave, press the power level button and press the number 8. This will automatically reheat your coffee at 80 percent of the maximum power level or two notches below the default power option, which is the right amount of power to reheat your coffee without burning it.

How long should you reheat your coffee? Well, that depends on how much coffee you’re reheating. Usually, a half-full coffee mug requires 45 seconds to reheat it properly, give or take a few. If your coffee isn’t hot enough after the estimated reheat time, just continue to microwave it in 30 seconds increments until it reaches that perfect temperature.

After a short trip in the microwave, it’s unavoidable that your coffee will taste bitter, just like any brewed beverages will. To fix it, just add sugar or creamer, and you’ll immediately enjoy your coffee again.

Final Thoughts

So there you have it! Whether you are reheating your cold cup of coffee or you just want to enjoy a steaming hot cup, microwaves can be a quick and easy way to do so.

Just remember: always use a microwave-safe container when microwaving your coffee, check for any damage to the container, and don’t reuse a styrofoam cup as it can damage the material.

Also, keep in mind that microwaves work on a power level basis, so feel free to adjust or experiment with different power levels until you find one that is best suited for your coffee’s needs. 

Looking for more tips on microwaving coffee? Check out our other posts on microwaving a coffee pot.

By Rosie Elliott

I’m Rosie. I’m a professional chef with experience in Western, Mediterranean, and Italian cuisine. I’ve been cooking for over 15 years, and I have two daughters that keep me busy!