How To Keep Your Chemex Coffee Warm

The downside of delicious Chemex coffee is trying to figure out how to keep it hot. Here are some solutions.

A person reaching for a cup of coffee with a Chemex carafe in the foreground

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Last Updated on December 13, 2023

Chemex is the biggest name in pour-over coffee. If you see a Chemex carafe, you know you’re in for a good cup of coffee.

But any Chemex coffee lover will tell you that although this coffee maker brews delicious coffee, the downside is trying to keep the coffee hot. The elegant glass design of this carafe doesn’t retain heat like a bulkier thermal carafe would.

With that said, we have a few tips for how to keep your Chemex warm.

Closeup of hot coffee in a Chemex carafe

Accessories for keeping Chemex coffee warm

The easiest way to help your carafe retain heat is to use these an accessory.

Chemex glass stopper or Chemex lid

A Chemex glass stopper or a Chemex lid is a great piece of gear for keeping your coffee warm.

Most of the cooling process happens when heat escapes from your Chemex through the opening on top. Placing a stopper at the opening will prevent evaporation and help keep your coffee hot.

There are several options when it comes to Chemex lids. Coffee aficionados can opt for a glass stopper in line with the Chemex style, or a bamboo or silicone lid with a lower price tag.

Mug cozy 

Sometimes the best coffee warmer is the one you’re drinking out of.

Your cup of coffee doesn’t just lose heat when it’s in the carafe, it also loses heat while it’s in the mug. A mug cozy will keep your coffee warm and have you feeling like you’re drinking out of a thermal carafe.

Pairing a mug cozy with a Chemex carafe cozy is a great way to ensure minimal heat loss throughout your morning coffee routine. 

Chemex Carafe cozy

Coffee cozies aren’t just for mugs. You can also get a cozy for your entire Chemex carafe.

The thin glass walls of a Chemex carafe don’t do a very good job of retaining heat. Adding a cozy to your Chemex will give it an additional layer of insulation that will help keep the heat in your coffee.

There are tons of brands of Chemex carafe cozies out there, but we like the stylish Hexnub version made of neoprene fabric that won’t easily transfer heat. 

Get a good thermos

If you’re looking to skip the cozies, you can always pick up a great thermos. 

A thermos is a classic way of drinking coffee and there’s a size out there that’s right for you. Most thermoses have an insulating layer. This can either be a layer of carbon as seen in most classic thermoses or a vacuum seal like we see in modern thermoses.

The trick to getting a great thermos is to spend a little bit more than you think you would. That discount plastic thermos isn’t going to do a much better job than your standard mug when it comes to retaining heat.

You want something serious? Go for the Stanley Master Unbreakable thermal bottle.

Skip these coffee warmer gadgets 

There are a few gadgets that some people suggest when it comes to keeping coffee hot. However, these might be a little bit more trouble than they’re worth.

Some people have suggested using a candle warmer to keep your Chemex coffee hot. The big problem with this is that a candle warmer is simply not designed to heat something as large as a Chemex carafe. There’s not going to be a lot of heat moving between those scented candles and your Chemex.

You can also save some time and skip heated blankets and immersion heaters. While these options will technically keep your coffee hot, we’ve got some better coffee hacks in store for you. 

Can you put a Chemex on a stove?

Why not return your brewed coffee to the same heat source that gave your morning pick-me-up its warmth in the first place? 

Before we get into how you can heat your Chemex on a stove, we need to go over the one basic rule of heating a glass carafe over an open flame: Never place an empty glass carafe onto a heat source. This can cause the Chemex to crack and shatter. Always make sure there is some liquid in the Chemex carafe when it’s being heated.

Now let’s take a look at how you can heat a Chemex on the three most common types of stove. 

Warming Chemex coffee on a glass stove

You can heat your Chemex carafe directly on your glass stovetop.

The only thing to keep in mind with this method is that some glass stovetops are induction heat sources. These have difficulty heating glass and are better suited for heating steel or iron.

A glass stovetop has the lowest chance of leaving carbon burn marks on your nice Chemex carafe. 

Warming Chemex coffee on a gas stove 

You can use a gas range to keep your Chemex coffee hot.

The trick to putting your Chemex on top of an open flame is to keep an eye on the time. Heating a Chemex on top of a stove for hours runs the risk of spoiling the coffee’s flavor and potentially breaking your Chemex.

Chemex coffee maker on gas stove
Low, low heat is the key to warming your Chemex safely on a gas burner. (© H. Michael Karshis | Creative Commons)

Make sure to keep the flame as low as possible and remove the Chemex when the liquid level gets low.

One thing to keep in mind with heating your carafe over open flame is that this will leave carbon marks on the bottom of the glass. These are normal burn marks left by the flame that are very difficult to clean off your Chemex carafe. It might be worth experimenting with other coffee heating options before putting your Chemex on an open flame. 

Warming Chemex coffee over an electric element 

An electric element is the riskiest way to heat a carafe of coffee on a stovetop.

That electric coil stove works just fine for cooking, but you’re taking your chances with your Chemex carafe. Those metal coils transfer heat very quickly. Even a full Chemex carafe can be cracked by this heat source.

Chemex does make a heat diffuser that you can buy and place on top of the metal coil in order to protect your carafe. However, even with that heat diffuser, your Chemex carafe can still crack. 

There are better ways to keep your coffee hot than risking it on that electric coil stovetop. After all, is a hot cup of coffee really worth breaking your Chemex?

If you’re at that point, try the options below instead.

Easy ways to keep Chemex coffee hot

If you’re not interested in buying additional Chemex gadgets or risking cracking your Chemex on top of your stove, we can’t blame you. 

Sometimes the best solutions are the most simple ones. These are a few coffee hacks that you can try today to keep your Chemex coffee hotter, for longer. 

Preheat your Chemex

Your coffee is going to lose the most heat the minute the hot water or coffee touches the side of a cool carafe.

One time-tested trick for keeping your coffee hot is to preheat your carafe before you start brewing with your Chemex.

All you need to do is boil a little extra water ahead of time and pour that into your carafe. The hot water will warm up the glass and minimize the amount of heat that gets snapped out when you start brewing your coffee.

Top view of a gooseneck kettle boiling water
Before you brew with that hot water, use some of it to heat up your Chemex carafe.

If you’re looking to retain heat even longer, you can give your carafe a warm bath.

Give your Chemex a warm water bath

Everybody loves a nice warm bath every now and then, and your Chemex carafe is no different.

Placing your Chemex coffee maker in some warm water is a great way to prevent heat from escaping during the brewing process. All you need to do is fill your sink with hot water and place your carafe in while the coffee brews.

You can also use this warm water bath trick to reheat coffee. The warm water won’t brew the coffee any more than it already is, so this method prevents the common problem of over-extraction.

Other ways of reheating coffee, like microwaves and stovetops, heat the coffee to the point where it starts brewing again, which causes the flavor to quickly become too bitter. A nice warm bath not only keeps your coffee warm, but also keeps it tasting great. 

Wrap your carafe in a scarf

No, really, try wrapping your carafe in a scarf.

Sure, you don’t actually have to use a scarf. You can use a towel or any similar piece of cloth. This effectively lets you create a DIY cozy that keeps your coffee warm.  

Best of all, you can try this today with something you’ve got around the house, whether it’s that scarf you tucked away for next winter or a kitchen towel.

Brew the right size cup of coffee

One great way to make sure your coffee stays hot is just to brew the right amount every time.

If you’re anything like me, you have a tendency to brew way more coffee than you need to. I’m a big fan of putting a fresh pot on every morning, but that also means  those last few cups can get cold before anyone drinks them.

One way to ensure your coffee is always hot is to brew less at a time. This allows you to drink the coffee while it’s still hot—with the trade-off being you’ll need to brew again if you want more.

You can think about this as a trade-off between brewing coffee in bulk and having it go cold, or having to brew more often but making sure the coffee is always hot. 

Master the craft of brewing coffee 

One of the reasons your local baristas are always delivering piping hot cups is because they’ve mastered this craft.

There’s a lot that goes into making an expertly crafted cup of coffee. This includes using the right brew times and selecting the right size coffee grounds. But temperature is important, too. If you brew at just the right temperature, not only will you extract maximum flavor from your coffee beans, but you should also be able to keep your Chemex warm long enough to enjoy it fully.

Fine brew,
Elegance lost,
Glass walls,
Thin as frost,
Warmth fades,
Taste cascades.

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