Can You Reheat Coffee in a Coffee Maker?

A woman standing in front of a stove top oven heating coffee in a pan.

I'll admit it – even though I love the taste of fresh coffee, I still drink leftover coffee all the time. Why dump half a pot of coffee just because you brewed it a few hours ago?

Sometimes I'm just being lazy, and sometimes I'm in a hurry and don't want to grind a fresh batch of beans. Either way, it's important to know how to reheat your coffee so that it tastes as good as possible.

So, can you reheat coffee in a Coffee maker? Reheating coffee in your coffee maker is not a good idea. Your coffee maker's heating plate will not bring the coffee back up to a safe temperature. Try reheating it in the microwave or brewing a fresh pot instead.

Reheating coffee in a coffee maker isn't just difficult; it also changes the flavor and makes your coffee taste significantly worse. Keep reading to learn how to enjoy fresh and delicious coffee every time.

Why You Can't Reheat Coffee in a Coffee Maker

There's one simple reason why you can't reheat coffee in a coffee maker: the warmer plate doesn't get hot enough.

Mr. Coffee 12-Cup Coffee Maker

Whether you're using a Mr. Coffee or a different kind of coffee pot, your coffee machine probably has a “keep warm” function. This means that the bottom of the coffee maker will heat up during the brewing process. If you leave your coffee in the pot, it stays warm for 2-4 hours.

This heated area is known as a warmer plate. Warmer plates don't really add heat to your coffee; they just help the liquid in the pot stay at a drinkable temperature.

If you have cold coffee in the pot and simply turn the coffee maker back on, the warmer plate will start heating up. Your old coffee might even get warm. But because it's just a warmer plate, your coffee won't get hot.

The Problem with Room Temperature Coffee

Lukewarm coffee doesn't taste very good, but that's not the only reason not to do this. It can actually be dangerous to drink coffee that's only a few degrees above room temperature.

Bacteria can grow in any environment that's colder than 165 degrees and warmer than 42 degrees. Health safety officials call this the “danger zone.”

If your coffee has been sitting out at room temperature for more than 4 hours, it's in the danger zone. You should probably throw it out and make a fresh batch.

If your coffee hasn't been sitting out for very long but has started to cool down, you need to heat it back up to a safe temperature. Your coffee maker's warmer plate simply can't do the job.

How to Reheat Coffee Like a Pro

If you have leftover coffee that you still want to drink, there are two easy ways to get it back to temperature. Both have their advantages, but most people agree that the stovetop method is the best. Still, I've used the microwave method more times than I can count.

The Microwave Method

When you're in a hurry, the microwave method is the way to go. Pour leftover coffee into your mug, put it in the microwave for about a minute, and enjoy.

I don't recommend microwaving coffee that already has milk and sugar in it. For the best taste, add these things after the coffee is already warm.

The only problem with using the microwave is that it tends to break down the aromas in your coffee. Aromas are responsible for most of the flavor, so you might end up with a bland cup of caffeine water. This is fine if you're in a hurry, but it's not ideal.

Related Article: HOW TO MAKE COFFEE WITH A MICROWAVE? (IT WORKS)

The Stovetop Method

The absolute best way to reheat coffee is on the stove. Pour your coffee into a small saucepan, and warm it up on a medium heat. Don't use full heat; you'll burn the coffee.

Take the coffee off the stove when it starts to gently simmer. If you go to a rolling boil, you might change the flavor of the coffee or make it too hot to drink.

The stovetop reheating method is also a great choice for concentrated cold-brew coffee. If you've ever made coffee using the drip brewing method, add a little water and warm it up on the stove for a delicious-tasting cup.

How to Store Leftover Coffee

Like any other type of food or drink, coffee can go bad if it's not stored correctly. Don't just leave your coffee sitting in the pot – it won't be safe to drink when you come back to it.

The best place to store leftover coffee is in the fridge. If you aren't planning to use your coffee maker anytime soon, you can just take the glass carafe and stick it on one of the shelves in your fridge. Just like that, your coffee is safe.

For a slightly classier storage method, try pouring your old coffee into a glass jar. Remember to screw on the lid so that nothing can get into your coffee while it's in storage.

Jarred coffee is still good to drink for 1-2 weeks. Don't pour coffee from multiple batches into the same jar. If you do this, know that the coffee is only as good as the oldest batch that was poured in. And seriously, don't do this.

If you don't have glass jars, you can also any kind of sealable container. Only use a plastic container if the coffee has already cooled down. Otherwise, you'll melt the container.

Once you've stored your coffee, you don't necessarily have to drink it. Cold coffee is an interesting component in both sweet and savory recipes. Try adding it to gravy, making it part of a marinade, or using it in a dessert.

What Not to Do When You're Reheating Coffee

Reheating coffee is all about preserving the flavor and making sure that your leftover drink is safe to consume. While you're experimenting in the kitchen, there are a few methods that you definitely need to avoid.

  • Don't leave your coffee out overnight. Like any food item, it could develop bacteria and become unsafe to drink.

  • Don't leave your coffee on the “keep warm setting” unless you plan to drink it in the next few hours. The longer that your coffee sits on the warmer plate, the more condensed the flavor will become.

  • Don't disable your coffee maker's automatic shutoff feature. If you forget to turn it off yourself, you could end up with burnt coffee all over the bottom of your glass carafe.

  • Don't pour old coffee into your coffee maker's water chamber. Coffee makers aren't easy to clean; if you run coffee through the water chamber, the taste of old coffee might never go away.

  • Don't put the glass carafe in the microwave. Coffee pots are not designed to be microwaved, so pour your coffee into a mug instead. You should also never put the carafe on the stove.

Instead of trying any of these dangerous or damaging methods, reheat your coffee with these simple rules:

  • Do store leftover coffee in the fridge so it doesn't develop bacteria.
  • Do reheat coffee in a microwave-safe cup if you're in a hurry.
  • Do make a fresh pot for the most delicious taste.

Why Fresh Is Always Best

You've probably heard coffee snobs say that fresh is always best. I'm not a coffee specialist, but I have to admit that a fresh-brewed pot tends to taste better. Obviously, fresh food of any sort is more delicious, but the flavor of coffee can actually degrade quite a bit over time.

Coffee is composed of delicate compounds that contribute to the flavor and smell. These compounds are not stable and will break down if exposed to air or water.

Air and water happen to be the two most important ingredients in the coffee brewing process. As soon as you grind your beans, they start to change. Once you've poured hot water over them, the chemical reaction hits full swing.

A brewed cup of coffee is essentially a mixture of water and aromatic oils that have been extracted from the coffee beans. If you drink the coffee right away, the balance of flavor is amazing. But the longer that you let that pot of coffee sit, the more the oils will break down and sink to the bottom.

Adding heat to the mix will also change the flavor components in your coffee. Those oils can burn, and burnt coffee tastes bitter and acidic. That's why you shouldn't leave coffee on the warmer plate for hours on end.

Related Questions

Can you still drink old coffee?

Yes, you can absolutely drink it, and it might even taste just fine. But if you want the best taste, you should use fresh beans and drink your coffee right away.

How long is old coffee still safe to drink?

Coffee that has been left at room temperature is safe to drink for 4 hours after it comes off the heat. Refrigerated coffee can be safe to drink for up to 2 weeks. When it doubt, make fresh coffee instead.

Why is my coffee maker brewing cold coffee?

If your coffee machine isn't working very well, you might need to clean it. Run a cycle with nothing but hot water. Then, combine water with a few tablespoons of vinegar and run it again. Go through one more cycle of pure water to finish cleaning your machine.

Why is my coffee maker turning off randomly?

Many coffee makers have an automatic shutoff feature. This is a safety feature that will turn off the coffee pot after 2 to 4 hours. Depending on the coffee maker, you might be able to change the shutoff time.

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