How To Reheat Coffee

Author: Melissa Collins

Updated: March 9, 2023

Drinking hot coffee is delicious and amazing. In the early morning, it’s the perfect thing for feeling alert. Sometimes, however, coffee ends up being left out longer than we intend it to. Is it okay to reheat coffee, and what are the best methods? Luckily, you have plenty of options when it comes to reheating your morning cup without sacrificing taste.

Can You Reheat Coffee?

The answer is yes–you can reheat coffee, as long as the coffee has not been sitting out for too long. The general rule of thumb is that coffee can sit for four hours before the oils begin to go bad. If you brewed a pot in the morning before work and you’d like to reheat a cup when you come home, make sure you transfer any leftover coffee into the fridge before you leave.

If you have kept your coffee in the fridge or your morning cup has merely gone cold, the good news is that it’s perfectly fine to reheat your coffee. There are a couple of ways you can heat it back up without ruining the taste or quality:

Reheating on the stovetop. This method will preserve the flavor more, and you will be better able to control temperature. You’ll be able to heat up the coffee slowly so that it doesn’t end up burnt. What to do: pour your coffee into a small pot and put in on the burner on low heat. Let the coffee heat up until steam rises from it–but don’t let it boil. Transfer the coffee back into your cup and drink up!
Reheating in a microwave. A microwave lets you heat up your coffee in no time. This is perfect if you’re in a rush, or are aiming simply for hot coffee and you don’t care as much about the taste. Change the power settings so you can use medium heat (avoid high power) for about 1 minute. Keep heating it in 30-second increments until it’s the ideal temperature. That prevents the coffee from burning. What to do: make sure your coffee is in a mug that is microwave-safe. Adjust your power settings and heat for 1 minute, then 30 seconds at a time.

The microwave and stovetop are the safest ways to reheat your coffee. It is not recommended to heat coffee in a convection oven or coffee maker. The oven will make your mug scalding hot, and a coffee maker is designed to keep coffee warm. If the coffee in your pot has long gone cold, you will need to take it out of the pot instead of turning the maker back on. Turning it back on will burn your coffee and potentially ruin the equipment.

It also should be noted that reheating is best for black coffee. If you have added cream, half and half, or non-dairy milk, you should avoid heating your cup up again. This is because dairy easily curdles and scalds. If you enjoy adding things to your coffee, it’s best to add them after you reheat just the coffee itself.

Dairy also goes bad after it has been left unrefrigerated for two hours. If your morning cup with cream and sugar has been sitting out for two and a half hours, you should throw the coffee out rather than attempt to heat it up.

The Ideal Temperature for Coffee

Ideally, coffee should be hot, but not too hot. The temperature of the drink can have an impact on taste because coffee that’s too hot turns bitter. On the other hand, a coffee that’s too cold will have a flat flavor far from the bold, full-bodied experience you’re used to.

How do you know what the perfect temperature is? You can go off of your local coffee shop. Most cafes serve coffee at a temperature of 180℉-185℉. Most people wait until it cools to 150℉ before they drink it, but some will ask their barista to make it extra hot because they like it that way, or want it to stay warm for longer.

If you steep your coffee at home or use instant coffee, it’s recommended to bring water to a boil but then leave it for up to 10 minutes before pouring it. Drip coffee makers will already be set up to heat water to a temperature of about 180℉ automatically, so if you use a regular coffee maker, you don’t need to worry about it.

Keep in mind that the “ideal temperature” will be different for everybody. The main thing is to prevent your coffee from burning or becoming bitter. Follow these best practices:

Turn off the coffee maker once it’s done brewing. Don’t let your coffee continue to be heated over a long period of time.
Heat water until it’s steaming, but not boiling, before you add it to your coffee. If it is boiling, wait a few minutes before pouring it out.
Be careful with the mug. Heating up a porcelain mug can make your cup hot to the touch.

Does Reheating Coffee Make It Taste Bad?

The way your coffee tastes will likely change once you’ve heated it back up. However, this change won’t necessarily be bad–it depends on your taste, and everybody is different. To some people, reheating coffee does make it taste bad. Others don’t mind, and even enjoy the taste of reheated coffee.

It’s perfectly fine to have different preferences. If you find yourself reheating coffee often, you can experiment with heating methods, times, and additives such as cream to see how it impacts the taste. After some testing, you’ll be able to nail down the reheating process that’s perfect for you.

There are ways to make sure that the taste isn’t altered too much. The biggest thing: Avoid burning your coffee or making it even more bitter during reheating. People who don’t like reheated coffee probably don’t like it because they burned it while reheating in the past.

Follow these methods to make sure your coffee doesn’t taste bad after you’ve reheated it:

Avoid burning the coffee and heating it for too long.
Keep an eye on your cup or the water you are boiling, and be mindful of your reheating method.
Add sugar to get rid of any bitterness.
Use flavored creamer to help mask any bad taste.
Don’t reheat coffee that has been sitting out for more than four hours. At this point, the oils will have gone bad, and heat may make the taste and quality even worse.

Overall, your coffee will change when you reheat it–but not too much. In the end, it is still a cup of coffee.

This Is The Best Way to Reheat Coffee

While there are many different ways to reheat your coffee, it’s widely agreed that there is one “right” or “best” way. A lot of people use the microwave to heat up their coffee, but it turns out that the stovetop is actually the better method.

A microwave is convenient and fast, but it can more easily ruin the flavor of your coffee and may not heat quite as evenly. The important thing is that using the microwave to reheat your coffee will break down the aromas that may be leftover from when the coffee was originally brewed.

What is a coffee aroma? It’s not just the smell: “Aroma” provides coffee its complete flavor profile. It’s the sour, sweet, salty, and bitter tastes that you experience when you sip your coffee. The longer the amount of time it’s been since the cup was first made, the more these aromas will break down–and a microwave will just speed up that unfortunate process.

Microwaves are fast, but you’ll quickly ruin the aroma of your coffee. This means your reheated cup is more likely to taste stale and bitter. At the very least, the flavor will be ruined. In other words, reheating your coffee in the microwave is exactly what gives it the potential to end up tasting bad.

So, what should you do? The best way to reheat coffee is to put it in a pot on the stove and let it heat up at low temperature. You can use any pot you have at home, then pour it back into a mug once it’s steaming.

Just remember to:

Keep the temperature on low. This distributes the heat more evenly and prevents the coffee from boiling. Once steam rises, you can have your coffee again–and you don’t risk frying or burning away all of the coffee’s flavor.
Be patient. It’ll take a while on the stove for coffee to properly reheat. It’s easy to lose patience and turn the temperature up, but this will burn your coffee and ruin the taste. Don’t rush anything.
Keep an eye on the pot. You can put your coffee on the stove and walk away, but make sure you’re constantly checking on it. At some point, the liquid will begin to simmer, then boil. You need to take it off the stove before bubbles begin rising, so check constantly or stay near the stove and watch the pot.

The next time your morning cup of coffee has gone cold or you stopped at Starbucks while running errands and saved it for later, skip the microwave and take some time to reheat your coffee on the stove. It does require time and patience, but it’s worth it in the end.

Is It Ok to Heat Up Day-Old Coffee?

Now you know that you can reheat coffee and which methods to use. But is it still okay to heat up coffee if it’s a day old? The answer depends on several factors, including exactly how long ago the coffee was brewed and whether it has any additives in it.

It’s perfectly fine to drink “old” coffee, but there are a few things you should be aware of. If you have day-old coffee and you’re wondering if it’s safe to reheat and consume, ask yourself these three questions first:

Is the coffee black?
When was the coffee brewed?
Was the coffee put into the refrigerator?

An important rule of thumb is that milk goes bad if it’s been unrefrigerated for two hours or more. If you added milk, creamer, half and half, or even non-dairy milk, you should actually just throw out the coffee if it’s been sitting out for hours. That way you can make sure you don’t end up getting sick from your old coffee. Black coffee is the safest to reheat–no matter which way you reheat it.

The next question is how long that black coffee has been sitting out, too. How long ago was the pot originally brewed? Another rule of thumb here is that after four hours, the oils within coffee will begin to go bad. This is when coffee becomes more acidic. Reheating coffee that was brewed an hour or two ago isn’t a bad thing at all–but if it’s 4pm and that pot was brewed at 8am, you should avoid helping yourself entirely.

However, it is possible to brew coffee, keep a cup in the fridge, and heat that up again. It’s safe to put coffee in the refrigerator. In this case, you can brew a pot at 8am, stick some coffee in the fridge, go to work, and heat up a cup when you come home. Just be sure that you drink that refrigerated coffee soon; it’s not recommended to have it in the fridge for longer than one day.

Summary

So, how do you reheat coffee, and is it safe? Remember:

You absolutely can reheat coffee. You can heat it up either on the stovetop or in the microwave, although the stovetop is the much better method.
Don’t heat your coffee on the stove or in the microwave for too long, otherwise, you will burn it and ruin the taste.
In general, reheating does not make coffee taste bad.
Heat your coffee to a temperature of 180℉ and remove it from the stove once you see it steaming.
It’s okay to heat up old coffee, but keep these milestones in mind: Unless it’s been refrigerated, coffee with creamer or milk should be thrown out after two hours and black coffee should be thrown out after four hours.

How to Reheat Coffee

If you love drinking hot coffee and your cup has long gone cold, don’t worry: You can reheat coffee without making it taste bad. Remember the two main reheating methods–microwaving and stovetop–and that reheating on the stove is best.

There are many ways to enjoy coffee. Heating it back up again is just one more way! The next time you need to give your coffee a boost, try putting it in a pot over low heat on the stove.