Why Do Coffee Cups Say Do Not Microwave?

Who else has noticed this statement, “do not microwave” on coffee cups? I have. A microwave is a piece of equipment that works with electromagnetic radiation – just like sunlight, radio waves, and x-rays. It is used to heat food or beverages. 

Most coffee cups say “do not microwave” because the glue used in sealing the side seam down the length of the cup doesn’t work well when it is microwaved. So, if you try to microwave your coffee cup, it will disintegrate the glue, and you will get a leak on the side seam of your coffee cup. Also, the coating inside the coffee paper cups is lined with a combination of wax and plastic and is made to hold hot beverages but cannot withstand the heat from the microwave. Sometimes, in extreme situations, it can make a coffee paper cup catch fire.

Microwaves usually stir up water molecules when passing through materials. If you have a liquid in a microwave-safe container, the increased speed molecules experience will heat this liquid. Still, if the container is not microwave-safe, then the glue component in the container would be affected, and you are likely going to experience a leak. 

Is it bad to microwave coffee cups?

It is terrible to microwave coffee cups that are not microwave-safe because of the way they are made. The way and plastic lining inside the paper cups can quickly melt and warp and seep into the coffee, thus, exposing them to too much heat that will tamper the taste of the coffee. 

Whenever I buy coffee that I know I cannot finish immediately, the first thing I do is check the cup to see if it is microwave-safe; if it is not, I don’t attempt to microwave it, so I don’t alter the taste of my coffee and ruin the coffee cup too. 

There are microwave-safe coffee cups; those are the types anyone can try to microwave.

What happens if you microwave a coffee mug that says do not microwave?

If you try to microwave a coffee mug that says, “do not microwave,” the coffee mug will be very hot in the microwave, and it can cause burns if your skin comes into contact with it. But if you give your coffee mug a while to cool down before touching it, it will be safe enough for future use. 

What is the best way to reheat coffee?

I don’t particularly appreciate reheating my coffee because I feel it’s too stressful. If I cannot finish the coffee in my coffee cup, I dispose of it or share it with a friend. But what I like may not be what you want. If you reheat your coffee in the microwave, it breaks down all the remaining aroma left from it when it was first brewed. By aroma, I don’t mean the smell of the coffee. Coffee aroma is the element in coffee that is responsible for everything that gives your coffee its unique flavor. It has to do with the salt, bitter, sweet, and sour taste in your coffee cup. Reheating your coffee ends up breaking down the natural aromas that will destroy the flavor and make your coffee taste unpleasant. When this happens, you may not like to drink your cup of coffee anymore. 

There are pretty many ways you can reheat your coffee, but the way I will recommend it to you is by heating it on the stove pot at a low temperature. When I use a stovetop to reheat my coffee, I don’t need to use any special spoon or pot to do it. I use any pot that I can find in my kitchen cabinet.  I need to maintain a low temperature when doing it; I don’t even need to hover around it or continuously stir it with a spoon. The first time I tried reheating my coffee with a stovetop, it came out well. You can also try it and see what will become of your coffee. Don’t allow your impatience to ruin your coffee; avoid increasing the temperature too high because if you do, it may burn the pot or make your coffee taste like burnt liquid. And trust me, you don’t want that to end up drinking burnt coffee. The primary benefit of this stove pot method is that you don’t risk burning your coffee at all. So, it is very safe. If you want to use the stove pot method to reheat your coffee successfully, you need to practice doing it very slowly.

So, below are the procedures involved in using the stove pot method to reheat your coffee.

  1. Turn your cold coffee into a small pot—coated cast iron works great because it is pretty slow to heat up but holds heat for a very long period.
  2. Please put it on the stove set to low or medium-low heat.
  3. Ensure you stir your coffee every few minutes.
  4. Inspect the temperature often.

You can also use the microwave method to reheat your coffee. But this method alters the flavor of your coffee rapidly. Also, indeed, you may not enjoy the best taste if you use the microwave method to reheat your coffee, but it is the fastest method you can use. 

Below are steps on how to use your microwave to reheat your coffee. 

  1. Select a microwave-safe mug.
  2. Pour your cold coffee into the microwave-safe mug, leaving it about ¼ empty (just in case you overheat it and it boils).
  3. Close your mug with a paper towel before keeping it in the microwave. 
  4. Then, heat it for about 30 seconds.
  5. Stir your coffee before testing the temperature; if it’s not hot enough, microwave it for another 10 seconds at a time, stirring between bursts, until it reaches the required temperature.

If you notice an “off” flavor after microwaving your coffee, you can add flavor enhancers to cover it, and using your cream is a perfect way to protect a flavor change. You can also try using flavored creamers; they work excellently well too.

The thing is that if your coffee was already flavored, you might find it challenging to observe a change in the taste. You may also choose to reduce the power on your microwave and take it much slower. This will help you prevent a “burnt” flavor.

You should be the one to decide if you want to reheat your coffee or not and choose which method is best for you too. Avoid any pressure from anyone. If reheating is not your thing, stay away from it.

Is reheating coffee unhealthy?

Reheating your coffee is not unhealthy. But I don’t particularly appreciate drinking reheated coffee. If you don’t use the best reheating method for it, you will change the original taste. However, there are no terrible health effects if you drink your coffee after reheating it.

I reheat my coffee sometimes, but I make sure I use the best method of reheating it. 

Why are ceramic mugs not microwave-safe?

Ceramic mugs are not microwave-safe because their paint gas materials attract microwaves and cause the mug to get extremely hot. Many ceramic mugs producers still go ahead to inscribe on their products that they are microwave-safe when they are not.

Certain types of ceramic mugs are microwave-safe; some of them are stoneware and porcelain.

Can you microwave Wawa coffee cups?

Have you tasted Wawa freshly brewed coffee before? The taste is fantastic. I love to drink their hazelnut and French vanilla flavor of their mild roast coffee. 

Wawa coffee cups are made from a mainly plastic material; hence it is not suitable for you to microwave them, especially when they carry the “do not microwave” inscription on them. 

What happens if you microwave a Starbucks cup?

If you microwave a Starbucks cup, the high temperature of the microwave will make the materials that were used to produce melt and leak into the beverage. 

Why do McDonald’s coffee cups say not to microwave?

McDonald’s coffee cups say, “do not microwave” simply because they don’t want me or you to. If you try to, you will create a leak in your McDonald’s coffee cup and destroy the natural taste of your coffee. 

I have taken a closer look at many McDonald’s coffee cups before, they look like paper, but they are coated with a thin layer of plastic on the inside. The plastic coating in it keeps the cups from leaking, and it is not microwave-safe Also, the paper cups are excellent for hot drinks to-go but are not great for reheating or microwaving. If you intend to reheat it, I recommend that you transfer the coffee to a glass, ceramic, or pyrex cup. The designers of McDonald’s coffee cups designed them to hold hot drinks but not to withstand the excessive heat. This beautiful extreme heat can melt the plastic coating, leach chemicals into the hot cup of coffee, and eventually cause a leak from the cup.

How do I tell if a McDonald’s coffee cup is microwave-safe or not?

It is written on the cup for you and me to see it. It carries the inscription, “do not microwave.” 

Although I can also test the microwave safety of my McDonald’s paper cup by simply filling the cup half full of water and leaving it in the microwave for about thirty seconds if my cup is cold and the water runs warm, it shows that it is microwave safe. Still, if the cup is warm and the water is cool, it means the cup is not safe for me to use in the microwave at all. 

If I want to reheat my McDonald’s coffee, I transfer it to a microwave-safe cup rather than using the McDonald’s coffee cup that is not microwave-safe. McDonald’s coffee cups are produced to transport hot coffee and not for reheating. Although it only keeps a beverage hot for less than an hour based on the surrounding temperature.

How I reheat my McDonald’s coffee in a microwave.

I reheat my McDonald’s coffee-based on whether my coffee is black or has dairy mixed in it like a cappuccino or latte because I use different microwave power levels for them

  1. If my remaining coffee contains dairy, I heat the coffee to 165°F or 74°C to prevent the growth of bacteria.
  2. I begin with a low setting before increasing the time to heat the beverage without scalding the cream or milk fully. 
  3. Then, I transfer the beverage to a microwave-safe mug to reheat my coffee.
  4. I avoid trying to cover it with a lid.
  5. I use 30-second increments to reheat my coffee in the microwave.
  6. Also, I sometimes stop to stir after each time frame. 
  7. Microwaves heat unevenly, so it is best to stir often to distribute the warmth.
  8. When I am removing my heated coffee, I use a glove or towel to touch my coffee cup because my cup and handle may be burning hot, so I try to be careful.

The procedures involved are straightforward. The next time you buy a cup of McDonald’s coffee, you can try reheating it using the methods I listed out above.

Conclusion

Avoid trying to microwave a coffee cup with the inscription “do not microwave” on it; you will end up burning it or creating a leak in it. It is not wrong to microwave your coffee. Just make sure the coffee cups you are using are microwave-safe. If the coffee cup your coffee came in is not microwave-safe and you want to reheat it, transfer it to a microwave-safe cup to reheat it. 

If you want to drink your coffee after abandoning it, try reheating it using the stovetop method. This method of reheating your coffee prevents it from getting burnt, but you need to use a low temperature for it and wait patiently. Reheating your coffee is not unhealthy, but if you don’t do it properly, you might end up ruining the taste of your coffee.

I prefer freshly brewed coffee to reheated coffee, so I do my best to avoid consuming reheated coffee. Don’t allow anyone to pressure you into drinking reheated coffee; if you don’t like it, stay say from drinking it.