How Long To Microwave Coffee? How to Best Reheat Your Coffee

crazy by Editorial Staff | Updated on August 16th, 2022

Is it possible to make coffee in the microwave? You certainly can. But are you sure you want to?

Microwave coffee is quick and easy to make. Assume you’ve been working for a while, gotten lost in the zone, and reached for your cup. It’s freezing! Should you make a new cup or reheat the one you have?

cup microwave

If you have a grinder and a coffee machine on hand, take a break and prepare a fresh batch. But even if you only have the office microwave, you can make it work.

How long does it take to heat up coffee in the microwave?

Instead of paper or styrofoam cups, always use microwave-safe mugs. Begin with a half-filled cup, set the power to medium-high, and nuke for 45 seconds. If the liquid is still warm, continue to microwave in 30 second increments until it reaches the appropriate temperature.

If you reheat old black coffee in the microwave, you may notice a more bitter taste. To alleviate the harshness from the reheated coffee, simply add a dash of creamer or sweetness.

Is it possible to reheat coffee in the microwave?

The microwave is the most convenient way to quickly reheat food and beverages; heating up coffee is no exception!

You may heat up coffee to achieve the required level of warmth. Heating coffee, on the other hand, may alter the flavor by making the beverage taste slightly bitter.

When coffee cools, the chemical components shift and the acidity level rises. As a result, warming coffee with fast heat accelerates the breakdown of aromatic compounds, resulting in an acidic taste.

It’s critical to understand that not every cup of coffee is reheated in the same way. Based on individual brands and serving techniques, below are the best microwave coffee heating methods:

  • Starbucks: serves specialized coffee beverages in reusable containers such as plastic cups and glass bottles. The ceramic mug is the sole microwave-safe container. Make sure to test it out and heat it for 30 seconds at a time to get the ideal temperature. You may keep freshly made coffee in a Starbucks tumbler, but if it’s double-walled vacuum-sealed, avoid putting it in the microwave.
  • McDonald’s: McDonald’s coffee cups, however, are held together along the side seams with plastic and wax covering. As a result, they cannot be microwaved since the adhesive layer may melt and leach into hot coffee.
  • Dunkin Donuts: Dunkin Donuts coffee beverages were once served in styrofoam cups to keep hot drinks hot for extended periods of time. In recent years, however, they have produced double-wall paper cups as an environmentally beneficial disposable product.

If you’re going to use the microwave to reheat a lukewarm coffee, ensure sure the cup is microwave safe. As it turns out, most to-go cups should not be microwaved.

Is it dangerous to microwave coffee?

smoking coming out of microwave

Although microwaving coffee alters the flavor and taste, there is no link between reheated coffee intake and negative health problems.

However, reheating coffee in non-microwave-safe paper or plastic cups may leach glue, plastic, and wax components into the hot drinks, which you should avoid.

Microwaves emit electromagnetic radiation, which is not dangerous to liquids unless the kitchen device contains metal, plastic, or styrofoam.

Microwaving a cup of coffee agitates the water molecules, causing the atoms to travel faster and induce friction, which generates heat. The electromagnetic radiation will not fundamentally damage the liquid’s structure, but what happens to coffee when microwaved?

What happens when coffee is microwaved?

Before you microwave a cup of coffee, find out what happens to coffee when it’s heated.

According to the study, coffee contains approximately 1,000 distinct chemical components in addition to caffeine. As a result, each coffee bean has a unique flavor character.

The growing environment, soil conditions, when the beans were gathered, and how the beans were dried, stored, and roasted all have an impact on the flavor of coffee. There are several variables and actions that can have an impact on aromatic compounds, either positively or negatively.

When you microwave coffee, the heat waves break down any odors left behind from freshly made coffee. The scent in this context refers not only to the smell, but also to the sour, salty, bitter, and sweet taste. Aroma disintegration ultimately alters the flavor and causes your coffee to taste stale.

Caffeine is regarded as one of the most vital components of coffee since it keeps us aware and awake in the morning. Do you believe that warming coffee in the microwave lessens the quantity of caffeine?

Is it true that microwaving coffee removes the caffeine?

Caffeine is a massive, hefty, non-volatile molecule that does not lose its properties easily. Although there may be a change in flavor as a result of the cold coffee coming into touch with air, warming in the microwave does not destroy the caffeine.

Caffeine does not evaporate or dissipate after microwaving, regardless of when it was made. The caffeine content of your coffee remains constant between five minutes and five hours. However, there will be somewhat more caffeine owing to water evaporation, which raises caffeine concentration in reheated coffee.

Caffeine can only be removed from coffee by processing green coffee beans. There are three methods for decaffeinating coffee, but each method employs wet green or roasted beans to take out caffeine.

However, merely microwaving coffee will not cause caffeine to evaporate during the reheating phase. Caffeine can only be eliminated before the final coffee beans are roasted and ground.

Do all coffee roasts, dark, medium, and light, become bitter when reheated?

To some extent, warming any form of roast will make it taste more bitter. The bitterness of a dark roast coffee, on the other hand, will be more prominent.

Because a dark roast has had more heat applied to the beans throughout the roasting process, it will contain more of the bitter-tasting quinic and caffeic acids than lighter roasts in the first place.

What about coffee with milk, creamers?

Milk and other perishable items should not be left out of the fridge for longer than two hours. Bacteria may develop in just one hour outside of the fridge in the heat. As a result, warming coffee with milk in the microwave may be a nightmare. The dairy may cause germs to grow in your mug, and the microwave won’t heat it evenly enough to kill all of it.

Before you microwave your coffee, there are a few things you should know.

Whether you’re reheating homemade coffee or Starbucks leftovers, there are a few things you should know before microwaving coffee.

Instead than preparing a new cup of coffee or heading to the store, microwaving cold coffee is a simple way to get a caffeine boost.

However, warming coffee in any manner might dilute the pleasant scents and make the java taste harsh. To compensate, add a dash of your preferred creamer and sweetener.

How to reheat coffee in the microwave

using the microwave

The best technique to reheat coffee in the microwave is as follows:

  • Use a microwavable cup.
  • If the cup isn’t labeled for microwave usage, test it by filling it halfway with water and nuking it for 30 seconds. It is deemed microwave-safe if the water is hotter than the cup.
  • If you are unsure, place the coffee in a microwave-safe mug before reheating.
  • While microwaving, avoid firmly fitting the lid. While air is trapped within the container, it may melt, superheat, or explode.
  • To reheat in the microwave, use medium power.
  • Stop and stir every 30 seconds to ensure that the temperature is uniformly distributed.
  • Keep leftover coffee or lattes in the refrigerator to avoid mold or spoilage of the dairy in the beverage.

How to Make Microwave Instant Coffee

Perhaps your office brewer isn’t a coffeemaker-grinder combination, and you’re out of grounds and don’t have access to a grinder. Or perhaps you’re locked in the library doing last-minute cramming and have just an electric kettle and a microwave at your disposal. You’re desperate, so you’ll have to settle with instant coffee.

To make instant coffee in a microwave, you have two options: boil plain water and stir in coffee, or combine all of your components in a cup and microwave it. The latter strategy is simpler and more straightforward in several respects.

But keep in mind that the scent of coffee is half the fun. So, if you put instant coffee in a cup of water and then microwave it, the majority of the scent will be expelled within the microwave. As a result, the aroma will be absorbed by everyone in the room, leaving you with none!

So just heat your water in the microwave, and make sure it’s pure water with no sugar, milk, or additions. These ‘extras’ will alter the way the liquid boils, perhaps making it more explosive.

Microwave Filtered Coffee Brewing Instructions

If you know how to make decent coffee, you’ll be able to brew coffee in a microwave that meets your expectations. There’s no reason to settle for a mediocre brew.

The idea is to think of the microwave as merely a way to heat water for brewing.

How long does it take boil water on microwave? A cup of water takes about 1 to 3 minutes to boil in a normal microwave. A basic microwave has a power output of around 700 watts.

The water must reach 200 degrees Fahrenheit and be clearly bubbling. You may not enjoy your coffee so hot, but such temperatures are required to extract the taste and fragrance from your microwave coffee blend. Use a microwave-safe cup or carafe that is clear.

And don’t fill it all the way to the top! The water need space to bubble without spilling. Spilled water isn’t a huge concern, but it’s hot, so you’ll be burned. You’re also probably in a hurry because you’re brewing in a microwave. There’s no time for cleaning! To avoid chilly areas, insert a toothpick or a popsicle stick into the cup.

Other Items to Keep Your Coffee Warm

Isn’t it always the case that someone lets their coffee cool? There are gadgets available nowadays that will keep your coffee at the proper sipping temperature.

Mug with a lid

A cup with a lid is a simple method to keep your coffee warm. A reusable cup, for example, can keep your coffee nice and warm for a bit longer. This will not keep your coffee as warm as a thermal cup, but it is better than nothing.

Mugs with Thermal Insulation

Thermal mugs have been around for a long time and are an excellent method to keep your coffee warm.

They also make excellent travel mugs for those early morning journeys!

When looking for the best thermal cup to keep your coffee warm, seek for an auto-seal locking lid that is also easy to clean. Depending on how long you want to keep your coffee heated, your options may alter. Look for a double-wall vacuum-insulated model, particularly made of stainless steel, to keep beverages warm for longer.

Stainless steel will cost more to buy, but if heat retention is important to you, this is the thermal mug for you.

Most manufacturers claim that beverages will keep hot for four or more hours.

Check out some of our articles for the best coffee cups

Best coffee ceramic mugs

Best double-walled Coffee mug

Best reusable coffee

Best Tumbler

Smart Mug

Smart mugs are a more expensive alternative in the cup market. The manufacturers of these mugs say that their goods can keep your beverage at the temperature you like for extended periods.

Using the Ember smart mug as an example, it is estimated that when used on the move with a preset temperature, the cup will last for 2 hours on batteries. The pour temperature, ambient temperature, and intended temperature are all factors that will affect battery life.

The smart mugs communicate with your phone via an app (or Apple Watch). You will be able to manage the temperature and track your caffeine use. An LED on the side will alert you if the drink becomes too hot.

Smart cups are not dishwasher safe and must be hand-washed after use.

The Best Way to Reheat Coffee Without Using a Microwave

While there are several methods for reheating coffee, it is usually accepted that there is one “proper” or “best” one. Many people use the microwave to make their coffee, but it turns out that the stovetop approach is superior.

A microwave is quick and easy, but it may quickly spoil the flavor of your coffee and may not heat as evenly. The crucial thing to remember is that using the microwave to reheat your coffee will break down any scents that may have remained from when it was first produced.

What exactly is a coffee aroma? It’s not only the smell: “Aroma” is responsible for the entire flavor profile of coffee. You’ll notice sour, sweet, salty, and bitter flavors when you drink your coffee.

The longer it has been since the cup was prepared, the more these scents will degrade–and a microwave will hasten that terrible process.

Microwaves are speedy, but they rapidly destroy the scent of your coffee. As a result, your reheated cup is likely to taste stale and harsh. The taste will be damaged at the very least. In other words, warming your coffee in the microwave causes it to taste terrible.

So, what are your options?

The easiest approach to reheat coffee is to place it in a pot on the burner and heat it slowly. You may use any saucepan you have on hand and then pour it back into a cup once it’s steamed.

Just keep in mind:

  • Maintain a low temperature. This uniformly distributes the heat and keeps the coffee from boiling. You may enjoy your coffee again after the steam has risen–and you won’t risk frying or scorching away all of the taste.
  • Please be patient. It will take some time on the burner to adequately reheat the coffee. It’s tempting to lose patience and crank up the heat, but this can burn your coffee and damage the flavor. Nothing should be rushed.
  • Keep a close watch on the pot. You may leave your coffee on the burner and go about your business, but keep an eye on it. The liquid will eventually begin to simmer and then boil. You must remove it from the heat as soon as bubbles appear, so keep an eye on it or stay near the burner and keep an eye on it.

Skip the microwave and reheat your coffee on the stove the next time your morning cup of coffee has gone cold, or you stopped at Starbucks while doing errands and stored it for later. It takes time and patience, but it’s well worth it.


Coffee is a fan favorite that many people cannot live without from early morning to lunchtime. To get the best results, reheat coffee in the microwave on medium power and gradually increase the temperature rather than rushing with excessive heat, which can burn or scorch the coffee flavor.

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Disclosure: No compensation or free products were received in exchange for writing this review.


Editorial Staff

The editorial staff at Crazy Coffee Crave is a team of coffee enthusiasts & Baristas who enjoy the one thing we all think about as soon as we get up in the morning. Trusted by thousands of readers worldwide.