Can You Microwave Starbucks Cups? Is It Safe?

Since Starbucks cups are made of paper, you may assume they are microwave-safe. But can you microwave Starbucks cups? Paper cups include liners, not just Starbucks cups, but almost all paper cups cannot be heated. However, the plastic cup liner makes it harmful to microwave the cup. Starbucks coffee must first be transferred to a microwave-safe jar if you wish to reheat it.

The fact that a cup made to contain hot liquids cannot be heated inside the microwave may seem paradoxical, yet it is true. In this post, we’ll explain why Starbucks cups shouldn’t be used in the microwave.

How Do Microwaves Operate

Although we won’t turn this into a physics lesson, some familiarity with the operation of microwave ovens will enable us to see can you microwave Starbucks cups. Although microwave radiation is harmless, many individuals find the word “radiation” unsettling. Microwave ovens heat objects inside and out as opposed to conventional ovens, which cook food using hot air.

Microwave radiation becomes less energetic than the visible light that our eyes can detect. The water molecules in food vibrate in reaction to the microwave and heat when an item, such as a piece of food, is subjected to microwave radiation. The microwaves in microwave ovens are carefully tailored at their wavelength to excite water molecules.

Anything that includes water could be heated inside the microwave, but the microwave wouldn’t heat it if it didn’t contain any water.

Can You Microwave Starbucks Cups

Knowing more about how microwaves operate has made it easier to understand why reheating espresso in a paper cup isn’t a good idea. Paper can heat up and catch fire inside the microwave because it contains water, but the more immediate danger comes from other portions of the cup. Starbucks cups are mostly paper-based but have glue, wax, and a plastic lining.

Without a liner, paper cups won’t last more than a few minutes before becoming wet and leaking. Companies use plastic liners that keep the liquid inside to combat this. It is risky to microwave a cup with a plastic lining since the liner might melt and release chemicals or physical harm into the coffee if it contacts your skin.

You could believe everything will be OK if you don’t overheat the Starbucks cup, but that is also untrue. The glue keeping your cup together can be heated to the point of failure in just 10 to 15 seconds in the microwave. At most, you’ll have a minor leak to deal with; at worst, you can burn yourself on the hot coffee.

The Cups’ Material

can you microwave starbucks cups

Starbucks cups made of paper that can’t be microwaved have a plastic coating to make them waterproof and leak-proof. Because of this, Starbucks cups and other disposable cups cannot be recycled. The paper is ineffective in reheating food, in contrast to solid containers. If anything, it tends to disintegrate when subjected to intense heating, such as that produced by a microwave.

Harmful Leeching

As previously established, wax or adhesive keeps Starbucks cups together. Direct heat may cause these components to melt and spill into the beverage you will eventually consume. By drinking this beverage, you are putting a certain amount of pollutants into your body. Although the effects of these pollutants are long-lasting, your health will suffer greatly. As a result, it ought to be avoided.


Alternatively, your cup might begin to leak from the sides of the adhesive melts. It is not microwave-safe if your cup has a plastic or silicone coating.

Strange Taste

If you attempt to microwave your Starbucks cup, the coffee may not stay in the cup. The area of the cup with no coffee at the top is where the issue is. If it burns, the flavor of your coffee will change, and you don’t want that, do you? It is better to pour your coffee into a mug before microwaving it.


You may have heard of individuals who have gotten away with microwaving Starbucks cups. This suggests that there’s a remote chance you could microwave Starbucks cups. That is done, nevertheless, aware that the producers do not advise it.

This is so that a person may sue Starbucks over failing to provide a warning if they microwave the mugs and end up getting burned or in danger. Therefore, the “do not microwave” notice is a company’s responsibility. While you can technically microwave Starbucks cups, it’s not worth the risk. If anything goes wrong, it’s not the company’s responsibility.

What Other Options Do You Have

What will you do if you have to reheat your Starbucks cup of coffee now that it is crystal evident that you cannot microwave them? Depending on your location and the nearby heating sources, you may reheat coffee in various ways. You might, for instance, reheat your coffee at home by putting it in a pot and placing it over a burner.

can you microwave starbucks cups

The best way is this one since you can regulate the coffee’s temperature. If you have a microwave, you can also heat the coffee in a cup made of something other than paper or metal. Cups made of Styrofoam, glass, or ceramic would work well.

What Starbucks Cups Are Microwaveable

Can You Microwave Starbucks Cups That Are Reusable

For a slight discount, Starbucks offers reusable mugs and traveling cups that you may use in their establishments. These mugs are more likely to withstand the microwave because they are often constructed of plastic or ceramic. However, before putting the cup in your microwave, be sure it has a label indicating that it is safe.

Even other cups that, based on the material, appear microwave-safe are dangerous for other reasons. It might be difficult to determine by simply looking at a cup whether it can be used in the microwave or not if it does have a rubber gasket and metallic paint. If you can’t locate a label, your best option is to hunt for one and decide not to use it.

How To Check Whether A Cup Is Safe For The Microwave

Checking the care instructions is the simplest method to determine whether your cup—or any other item, for that matter—is microwave safe. The directions are often on the cup, depending on your use. For Starbucks cups, the instruction may be found close to the bottom.

“Microwave friendly” will be printed on the cup if it can be heated in a microwave. If not, its label may contain pertinent information or simply state, “Do not put in a microwave.” Make an effort to contact the maker via their website if the cup doesn’t include a label with care recommendations. Put a cup of water in the microwave.

The cup is microwave safe if it stays cold and has heated liquid. There is an unprofessional method to find out if the cup is microwave-safe.

Can You Microwave Starbucks Cups: How Long Must They Be Heated

can you microwave starbucks cups

When microwaves are used to heat molecules, each cup responds differently. Only use Starbucks mugs marked as microwave-safe, or start with one of those mugs. The answer to how long to microwave Starbucks coffee truly varies depending on the kind of coffee. Utilizing a little amount of time, temperature, and skill is the best method to microwave reheat coffee:

  • Half-full a cup made for the microwave.
  • Medium-high power should be used for the microwave.
  • Reheat in 30- to 45-second intervals.
  • After each interval, stir the coffee.
  • Reheat the food until it reaches the desired temperature.

You may determine the proper time by determining your coffee’s ideal warmth or desired temperature. This technique works great for black coffee, but be aware that coffee reheated from a fresh batch may taste slightly harsh. If there is milk in your coffee, be sure it has been chilled if it will not be consumed for further than two hours.

Milk is a perishable product that has to be refrigerated within two hours to help stop the formation of germs, according to Even though the coffee and milk have been combined, it’s never a great idea to exceed the USDA heat danger zone recommendations. If your latte complies with the safety requirements, use the same procedures to reheat it in the microwave.

Can You Microwave Starbucks Cups: Information To Consider

Is it okay to microwave Starbucks cups? Microwaving leftover coffee is a quick, simple, and effective method. The answer truly depends on the sort of cup you wish to microwave. However, if the manufacturer labels the cup as “microwave safe,” there should be a suitable marking on the cup’s bottom.

You may just heat one single serving of dripped coffee in the microwave rather than making an entire fresh pot. The following are the key details you should be aware of before microwaving a Starbucks drink cup:

  • Verify whether the cup is marked as microwave-safe on the underside.
  • If there is no label on the cup, perform a fast test by adding water inside and heating for 30 seconds. The cup is not microwaved safe if the water is warmer than the cup.
  • When unsure about the initial to-go cup, just put the contents into a cup or mug that can be heated in the microwave to eliminate any risk.
  • Always take the lid off the cup before putting it in the microwave.
can you microwave starbucks cups

Related Questions

Does Coffee Taste Odd After Reheating?

Most people feel that reheating coffee is useless since it alters the flavor. However, the coffee loses its freshness during brewing for 30- 60 minutes. As a result, the coffee’s flavor tends to disappear once it has cooled. Reheating your coffee might seem to make things better, but in reality, the flavor is diminished even worse.

This implies that if you allow your coffee to boil when reheating, the coffee’s quality will ultimately suffer. If you’re worried about the caffeine impact, don’t be; whether you reheat or re-boil your coffee, the caffeine is still there. Drink your coffee when it’s still fresh and hot for the finest flavor.

Additionally, if you have the money to buy a cup of coffee if yours becomes cold and you want to, do so.

How Long Should Freshly Brewed Coffee Be Left Out?

As previously said, you should consume your coffee as soon as it is still hot, ideally during the first hour of brewing. However, you may only leave your coffee out for a maximum of 12 hours. Drinking coffee beyond 12 hours poses a health risk. The coffee becomes a growing bacterial environment after being left for the previous 12 hours.

Furthermore, now that the coffee is at room temperature, the bacteria may grow on a nice surface. As a result, if you drink this coffee, you risk contaminating your system with bacteria and endangering your health. Within the first 12 hours, your coffee often has accumulated dust and other airborne particles in addition to bacteria developing.

Just think about how much filth you consume in the title of coffee. As a result, you shouldn’t consume coffee that has sat out for more than 12 hours. Additionally, remember to cover your coffee with a lid before leaving. You should complete the coffee whether you have already drank or touched it with your lips.

By tasting the coffee, you contaminate the coffee cup with microorganisms from your body and tongue. Therefore, if you leave your coffee, various germs will start developing.


Can you microwave Starbucks cups? Most people know that using metal in a microwave is dangerous, but most are unaware that using paper cups is equally dangerous. One would think that a cup made to carry hot liquids could resist the heat produced in a microwave, but because microwave ovens heat from the inside out, even vessels made to store hot liquids can malfunction in one.

The basic line is that you shouldn’t reheat coffee inside the microwave using paper cups from Starbucks. If you frequently need to heat coffee, you might want a reusable Starbucks cup; just check the label for a microwave-safe designation.

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