Is it Safe to Reheat Coffee in a Toaster Oven?

Last Updated on May 16, 2023 by Barry Gray

I’ve never been one to throw away coffee. Actually, that idea fills me with dread, which is why I’ve always been aware of how to reheat my coffee without destroying it. But while most people will think of using the microwave or cooker, how about another potential alternative? Can you reheat coffee in a toaster oven?

You can reheat coffee in a toaster oven, but you must be careful with how you reheat it, or you will destroy your coffee. You must reheat it slowly and at a lower temperature, or it will burn your coffee, and it will just not taste the same.

But I think the key here is the second sentence describing how you must reheat it slowly. That’s because coffee is more sensitive to reheating than most people think.

I’ve had to learn this the hard way resulting in coffee being thrown away as it just did not taste that good at the end.

I don’t want you to be in that position of throwing away coffee. It’s a horrible thought.

So, I’m pretty confident I can stop that from happening, and I will do so by taking up just a couple of minutes of your time.

How I Worked Out What to Do

I like to see myself as something of a coffee expert. I’ve tried countless roasts from all around the coffee-growing world, as well as any type of coffee drink you care to imagine. 

But dealing with reheating coffee was something I always tried to avoid by mainly drinking it at the one time, but where’s the fun in that? 

So, I decided to take things into my own hands and use my expertise in understanding coffee and the flavors and matching that up with how the flavor changed as I reheated my coffee.

I have to say that the results were surprising.

Also, I get that most people will automatically go ahead and use their microwave to reheat something, but what happens if it’s not working.

Should you go ahead and throw out your coffee?

That’s not what we coffee lovers do. Instead, we improvise and use whatever means necessary to get our coffee warm and enjoyable once more.

So, step forward the toaster oven because this device is more than capable of getting your coffee back up to temperature, allowing you to finish it off rather than throwing it away. 

Is it Difficult to Reheat Coffee Successfully?

poor coffee poured down sink

Let me begin by stating that reheating coffee is not easy.

It’s actually very simple for you to make a mess of things and destroy your coffee in the process.

The problem is you can burn your coffee, and most people will have to throw it away simply because it tastes terrible.

That’s a disaster, and it’s one we need to avoid.

The main issue you will face when trying to reheat coffee is the change in flavor.

It will taste more bitter than before, which you cannot avoid. It’s all thanks to chemical changes that occur when you reheat the coffee, and it will happen no matter the reheating method you decide to employ.

But here’s the important point I want to focus on.

You can limit how bitter or burnt it tastes by being careful how you go ahead and reheat the coffee. Yet I have a warning. It’s a fine line when heating your coffee, and it can quite easily go wrong. 

Also, there’s a particular technique associated with a toaster oven that could make or break your attempt to get your coffee tasting pretty good even after it has been reheated.

What Happens to Your Coffee When it Cools?

how does cool coffee taste?

Let’s face it, hot coffee generally tastes great, but I admit I start to struggle to enjoy it the same as it cools down. That is why knowing how to reheat your coffee correctly becomes so important.

But it also made me sit and wonder about what goes on as your coffee cools?

Why does it end up tasting so terrible as the temperature drops? To me, it’s almost as if the horrible taste increases as the temperature decreases, and it turns out there’s a good reason for it.

Now, I will need to dive into some chemistry and science for a short while here but stick with me, as it won’t take long.

Why Does Cold Coffee Taste so Bad?

Coffee contains something called lactones, and there are often more than 10 of them in coffee. Lactones contribute to the bitter flavors that come with coffee, so the combination of these lactones will change what your coffee tastes like.

However, as your coffee cools, these lactones break down into two different things – carboxylic acid and chlorogenic acid.

These two acids increase the acidity and bitterness of your coffee, which is why reheated coffee tends to taste more bitter than before.

The cooler your coffee gets, the more the lactones will break down, so that is why cooled coffee tastes so bad.

There is a real intensity attached to the flavor of coffee as it cools. Imagine how lousy coffee will be if you reheat it incorrectly and burn it in the process?

That takes the horrible flavor to a new level, and I cannot let it happen to you. 

Should I Preheat My Toaster Oven to Reheat Coffee?

toaster oven for warming coffee

This is something you should never do, and it’s for a very good reason.

People are used to warming up an oven before putting anything in there to heat, but it will lead to you destroying your coffee in an instant.

This is all because your coffee will be exposed to a lot of heat instantly, and while that may sound as if it will warm your coffee quicker, it will do nothing for the flavor.

Instead, you increase the risk of burning your coffee and creating an extremely bitter taste, and that’s not something we want. Your coffee will get too hot too quickly, and this is one of those times when slow and steady is the best approach.

Also, check the temperature.

Again, people make the mistake of thinking a higher temperature is best because it will warm your coffee in less time. Still, again, you will simply ruin your coffee in the process.

How to Reheat Coffee in a Toaster Oven

So, how do you successfully reheat coffee in a toaster oven? It’s actually relatively easy.

The key is the slow approach with your toaster oven set at a lower temperature and allowing your coffee time to warm up.

Also, here’s another tip, place your coffee in your toaster oven before it’s switched on. I’ll explain why that’s such a good idea.

A toaster oven takes some time to warm, which fits perfectly with the need to take things steady with reheating your coffee.

You allow your coffee to warm up in time with the toaster oven, and it will reduce the chances of your coffee tasting quite as bitter once warmed.

What is the Best Temperature for Reheating Coffee in a Toaster Oven?

I tried different temperature settings to see which temperatures would deliver the best-tasting coffee, and I concluded that setting your toaster oven to reach 200F is about perfect. 

I know this sounds like quite a low temperature. Still, I felt it delivered the best result, where the coffee was not too different in flavor and aroma from what you would expect with the freshly made cup.

Also, remember that you will be allowing your toaster oven to heat up to that temperature with your coffee sitting in the oven.

It does mean it takes some time to get up to temperature, depending on the model you own, but it really does produce the best end result for your coffee.

Is a Toaster Oven the Best Way to Reheat Coffee?

hot americano

I have to say that a toaster oven is not the best way to reheat coffee, and I say this for several reasons.

I think my main reason is it does take too long.

There are other methods out there that will reheat coffee in a fraction of the time, which means a microwave, and people will often not have all that spare time to wait on coffee to warm up.

However, it’s good to know you do have other options available. 

Can You Reheat Coffee with Milk in a Toaster Oven?

Suppose you have included milk in your coffee or even creamer. In that case, you can still go ahead and use a toaster oven to successfully reheat your coffee.

However, the same rules do apply regarding heating it slowly and gently. 

Actually, it becomes even more important in this instance because of the possibility of burning the milk and your coffee.

Also, I’ve discovered that you need to take extra care when reheating coffee that contains milk. It’s even easier to overheat the drink and ruin it in the process, so you must pay particular attention to what’s going on.

I would suggest keeping your toaster oven at that 200F figure I mentioned earlier, but check on your coffee more regularly than you did before.

You are not looking at trying to get your coffee piping hot, as that will ruin it, but rather to ensure your coffee is at an enjoyable temperature to allow you to finish consuming it.

My Recap for Reheating Coffee in a Toaster Oven

I’ve discussed how it’s possible to reheat your coffee in a toaster oven, but I did cover several key points.

So, to help you out, here is my recap regarding the most important pieces of information I feel I’ve covered.

  • It is possible to reheat coffee in a toaster oven
  • You must use a low temperature and heat things gradually
  • A temperature setting of 200F is perfect
  • Place your coffee in the toaster oven before it’s switched on
  • Allow your coffee to warm as the toaster oven warms up at the same time
  • Coffee with milk can be warmed in a toaster oven
  • Check regularly to prevent overheating
  • Heating too quickly leads to burnt and bitter coffee

I certainly had some fun trying to work out the best way to reheat coffee in a toaster oven. However, I still feel a microwave is the better solution thanks to its speed and convenience.

To Conclude

You can reheat coffee in a toaster oven but must take care to end up having coffee that is still a pleasure to drink. Take it slowly and at a lower temperature than expected, but pay close attention. It doesn’t take much for your coffee to burn, which would be a disaster.