Can You Reheat Coffee? (How To Get Good Tasting Old Coffee)

Hot coffee in the morning is the perfect way to lift your energy and kickstart your day, plus it provides some health benefits. But sometimes you're short on time. You get on with your tasks and then realize you left your coffee on the side.  

That’s when you might ask, ‘can you reheat coffee?’. You’ll want to read this guide before you try. We’ll cover whether it’s ok to reheat coffee and how to make sure your old coffee tastes great. 

Reheating old coffee causes significant flavor changes.

It gets a rancid, sour and bitter taste. Not only can it taste bad, the pleasant smell of coffee disappears too. 

However, similar consequences happen if you leave the coffee cold, although the oils in cold coffee will only go bad after around 4 hours. 

If you’re wondering why does reheated coffee taste bad, it’s because the chemical composition of the cold coffee is changed during the reheating process. 

However, reheating day-old coffee won't affect the levels of caffeine present, which is a bonus as that means the coffee will give you the same energy boost. 

Can You Reheat Coffee? (How To Get Good Tasting Old Coffee)

Besides the disadvantages when it comes to taste and smell, there are no health problems to experience as a result of reheating coffee. After all, it’s still the same ingredients that you put in at the start so when you drink the coffee it's the same ingredients as freshly brewed coffee.

Only the oils degrade, causing the bitterness to increase and the scent to fade from your morning cup of coffee.  

Can You Reheat Bulletproof Coffee? 

Bulletproof coffee is a high-grade coffee made using coffee beans, unsalted butter, and Brain Octane Oil. It’s creamy and looks like a latte. Reheating this type of coffee is essential if it goes cold because the oil and butter solidify, making it unpleasant to drink.  

Can You Reheat Coffee With Milk Or Cream? 

If you drink coffee with milk or cream in it can still be reheated, but only if it’s not been left overnight. That’s because bacteria love to grow in cold coffee that’s been left a long time, and adding milk or cream to the mix only encourages it. This is even more true for hot milk.

However, if your brewed coffee has milk or cream but has only been out a few hours, then it should be fine. Just make sure you don’t heat it too quickly, as hot milk and cream can scald and curdle.  

Can You Reheat Cold Brew Coffee? 

Cold brew is typically an iced coffee so you might not want to heat it, but some people actually enjoy cold brew coffee hot. You might wonder how to reheat cold brew coffee, but thankfully it's very easy.

The easiest thing to do is microwave the cold brew to warm it up. Or, if you're using a cold brew concentrate you can just use hot water instead of cold water to make your cold brew cup of coffee.

Some people really disagree with having cold brew coffee hot, but whether you should do it or not, you can reheat cold brew without any issues. It might seem odd given it’s an iced coffee to start with, but as you make the coffee warm it changes the flavor into a smoother and sweeter one. 

3 Best Ways To Reheat Your Coffee Again 

How to reheat coffee depends on your method of choice, and the best way to make brewed coffee warm from this list of methods will depend on your own experiences. 

Some coffee makers will have a hot plate to keep coffee warm or reheat it. This can be ok, but generally the prolonged heat will cause the break down of the coffee beans in the coffee and make it very bitter. We'd suggest avoiding this method.

Instead, here are 3 methods which work really well:

1. Microwave Method 

If you’ve ever wondered about reheating coffee the next day in a microwave, then you’ll be pleased to know it’s fine to do so. It works fast and reheats the coffee much quicker than a stove or convection oven would.  

However, you’ll want to make sure you don’t overheat the coffee or heat it too quickly. That way, you’ll preserve its consistency and prevent any milk or cream from scalding or curdling. It'll also stop you having burnt coffee.  

You can use a medium heat setting and leave your cold mug of coffee in there for 60 seconds. You can then take it out carefully and see whether it’s at a reasonable temperature. If not, give it a little longer. If it is, time to enjoy it!  

Some people claim microwaving coffee causes cancer, but most scientific studies demonstrate no link between the two. However, you might notice that microwaved coffee is more bitter. Some people have more sensitivity to taste changes than others, but it’s something you’ll want to keep note of when reheating coffee. 

As for how to microwave coffee specifically, here’s a rough guide: 

  • 1
    Grab your microwaveable coffee mug and fill it ¾ full with brewed coffee 
  • 2
    Cover it with a paper towel and put it in the microwave 
  • 3
    Heat it for around 30-60 seconds, stir it, and test to see if it tastes hot enough  
  • 4
    Keep microwaving for 10-second intervals and tasting in between until it’s just right 

So now you know the answer to ‘can you reheat coffee in the microwave?’ is a definite yes. That means your coffee reheating journey can be simple and fast using this reheating method.  

reheating coffee in microwave

2. Stove-Top Method 

You might be thinking about how to reheat coffee without a microwave if you don’t have access to one. So the next best option is to use the stove-top method. It’s slower but will still reheat your leftover coffee effectively. One of the main advantages over the microwave is that the flavor isn’t changed during the process, meaning your coffee will be as good as new.  

Despite the speed of reheating coffee being slower than a microwave, it’s still essential to slowly reheat your coffee on the stove-top. Your coffee will burn and taste terrible if you heat it too quickly. You’ll also want to use a suitable container that can be heated on a stove. 

Simply placing your mug of coffee on it probably isn’t a good idea, as it could get damaged by the heat. Instead, you can use a cast-iron coffee pot. These hold heat for longer too.  

As with the microwave method, here’s a quick guide on how to go about reheating coffee this way: 

  • 1
    Pour your coffee into the pot on your stove-top  
  • 2
    Set the heat on the stove to low, medium-low temperature, or an equivalent number 
  • 3
    Keep watch on the coffee and stir it every few minutes  
  • 4
    Check the temperature regularly so that you can guarantee it won’t burn 

Your results using this reheating method may vary slightly depending on the type of stove you have. Some are based on induction rings, and others use open flames. The thickness of the coffee pot you’ve chosen will also affect the time it takes to reheat the coffee and how soon it will be before it cools down again. 

So now you know the answer to ‘can you reheat coffee in the pot?’ is yes. You just have to ensure the coffee pots are suitable for the stove before you pour in your fresh coffee. 

3. Convection Oven Method  

If neither of the above methods suits you, then you might have asked, ‘can you reheat coffee in a convection oven?’ The answer is that you can indeed, but it’s not the best way, and that’s why we’re covering it last. Convection ovens, much like any oven, will make your mug of coffee very hot. That means you’ll likely need to pour the coffee into a fresh cup to make it drinkable. 

You’ll also need to be careful about the temperature because the air circulating throughout a convection oven will heat your coffee faster than a regular oven. That means you shouldn’t set the temperature too high, and you shouldn’t leave your coffee in the oven for too long. You can put it in for a few minutes and then see if it feels warm enough, but you should always leave the coffee out for a minute first, so it doesn’t burn your lips or tongue. 

What Is The Ideal Reheating Temperature For Coffee? 

When considering how to reheat coffee, you’ll need to know the ideal reheating temperature. Otherwise, you might end up making it too hot, which can make any milk or cream scald and curdle. Or you might not heat the coffee enough, and you’ll have to spend more time heating it. 

There are 3 temperature ranges that you can choose from for reheating coffee, and each one gives the coffee a different flavor. Between 120-140 degrees Fahrenheit, you’ll notice the reheated coffee has a taste that’s sharper, brighter, and more acidic. Between 155-175 degrees Fahrenheit, you’ll find the reheated coffee has bitter, sweet, and rounded notes. Finally, between 180-185 degrees Fahrenheit, after reheating coffee will have a warming sensation as you drink it.  

These temperature ranges are general for reheating coffee, so the best thing you can do is use them as guidelines until you find a temperature that gives you the familiar taste you love. 

Can You Refrigerate Coffee And Reheat It The Next Day? 

Refrigerating coffee is worthwhile if you need to do it, as it won’t make the coffee go bad and can preserve its oils for longer. However, there will be an unavoidable loss of flavor because coffee only retains its flavor for several hours.  

This results from the oxidation process, where oxygen reacts with the coffee and causes the flavor to decay. The same outcome is true if you are reheating coffee after it's been put it in a refrigerator, so the answer to ‘can you refrigerate coffee and reheat it?’ is yes, but only if you have to. Aim to use an airtight container for best results. 

How To Reheat Dunkin Donuts & Starbucks Coffees (Can It Be Done?) 

We’ll start by covering Dunkin Donuts coffee, and then we’ll look at Starbucks coffee. That way, you can compare both and see which one is the best for coffee drinkers to reheat.  

Dunkin Donuts approve of you reheating their coffee when you ask, ‘can you reheat Dunkin Donuts coffee?’, and their preferred option is using a microwave, although they mention it may take longer than using your stove-top or a convection oven. All you need to do is the following: 

  • 1
    Pour your Dunkin Donuts coffee into a microwaveable mug  
  • 2
    Place it in your microwave for 4 minutes and 30 seconds  
  • 3
    To add extra heat, add 15-second intervals until it’s at the temperature you desire  

On the other hand, to reheat Starbucks coffee depends on whether you need to do it. That’s because Starbucks says you shouldn’t reheat their coffee. They can’t guarantee the quality, and the cups are not microwave–friendly.

But, is reheating coffee bad if it's come from Starbucks? Not really, it works out ok and here's the method: 

  • 1
    Pour your Starbucks coffee into a microwaveable mug  
  • 2
    Use one of the methods we covered above to reheat the coffee  
white starbucks plastic cup

Frequently Asked Coffee Reheating Questions 

Can you reheat coffee in a Cuisinart coffee maker? 

The Cuisinart coffee machine reheat is generally a bad idea. If you use the Cuisinart coffee maker to reheat your coffee, it won’t reach a safe temperature just from using the hot plate. That means your coffee won’t be pleasant to drink. Instead, you should consider heating it in a microwave or making a fresh pot of coffee. 

Can you reheat coffee in a toaster oven? 

Can you reheat coffee in a toaster oven is a common question, and the answer is that you can. It’s easy to do and will get your coffee to the right temperature if you don’t leave it in there too long. It takes longer than your microwave and uses more electricity, so that’s worth keeping in mind.  

Can you reheat coffee in an air fryer? 

In most cases, ‘can you reheat coffee in an air fryer?’ is a question that you’ll receive a positive answer to. However, air fryers have a completely different heating process to ovens and microwaves, so the results will differ slightly. You might find that the surface of the coffee and the cup are hotter because of how the air circulates. Overall, we wouldn't recommend it.  

Can you reheat coffee in the pot? 

While some coffee pots can be reheated with the methods above, most have plastic and/or metal elements that make them unsafe for doing so. 


Is reheating coffee bad? No, not really. 

If you're brewing coffee and then coming back to it a few hours later to reheat your coffee then it's not going to cause you any harm. 

However, it can change the flavor and make it a bit more bitter, so don't expect it to have the same fresh coffee taste. 

Kayla Stavridis

Kayla Stavridis

Kayla Stavridis is the Head of Marketing here at Barista HQ. While keeping up-to-date on the latest trends in coffee, you can find her sipping a cold brew with just a touch of milk on the beach in the afternoon and a Corona with lime in the evening. She is passionate about keeping you informed about what’s new in coffee.

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