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Can I Heat Up Cold Brew Coffee? (yes, here’s how!)

I love cold brew coffee. But we don’t always want cold coffee. So if I have some in the fridge, can I heat up cold brew coffee?

As a general rule, it is possible heat up cold brew coffee. But the best way to drink cold brew coffee hot is to add hot water or creamer to it rather than heating the cold brew itself. This will keep the acidity lower and make it less bitter. 

But there’s a lot more to know about heating cold brew than just sticking it in a microwave. So let’s keep going!

However, if you want hot cold brew coffee, there are a few heating techniques that you will want to know about. In this article, we’ll review cold brew in general.

But we’ll also look at how it differs from traditional iced coffee. More importantly, we’ll answer the question of “can I heat up cold brew coffee?” And we’ll review the best ways of doing that.

Let’s dive in!

How do you heat cold brew coffee?

To heat cold brew coffee, the best-tasting method is to:

  1. First warm up the coffee cup by filling it with boiling water and then dumping it out. The effect is similar to when you’re at a restaurant, and your crisp salad comes in a cold bowl.
  2. Fill the coffee cup halfway with cold brew (ideally concentrate) and then finish it off with boiling water (but hot milk or creamer works too). This method results in a cup of coffee that is hot enough to warm your insides, but not hot enough to burn your throat.
  3. Alternately, heat the cold brew is by bringing it to a gentle boil on the stove

This may seem like a silly question to some.

But there are quite a few ways to heat cold brew coffee. And some of those are better than others. Something to remember here is that cold brew coffee is more concentrated than your traditional cup of joe.

For this reason, a great way to warm up this drink is by adding boiling water.

But if you’re looking for a way to drink it warm without watering it down, heating the cold brew itself would be a better option for you.

One thing to be cautious of is not to let it sit on the burner for too long, as this can result in burnt coffee. And you don’t want the coffee to reach the boiling point. So heat it over low heat.

Using a microwave is also an option, but it should be your last resort if you want to preserve the flavor.

Note: With all of these slow-heat methods, the rising temperature of the cold brew does give the coffee more time to oxidize, which can slightly change the flavor.

What happens when you heat cold brew coffee?

When cold brew coffee is heated, chemical reactions happen as chlorogenic acid and quinic acid, which are naturally present in the coffee become altered and release some of their properties into the coffee resulting in a more bitter, sour, and acidic taste.

Although there are over thirty types of acid in one cup of coffee, only those two I mentioned above come into play as you heat your cold brew: chlorogenic acid and quinic acid.

The other acids are much less affected by the heating process and lend themselves to the boldness and rounded flavors that we find in our favorite cups.

An excellent example of a time that you may have tasted hot-brewed coffee that was affected by these chemicals is:

  • At the airport
  • Fast food restaurants
  • A hotel breakfast
  • Or a greasy spoon diner

These places will often make a large batch of coffee and leave it sitting on a hot burner, sometimes for hours.

The upside of a large, long-burning batch is that you don’t need to wait for more than two seconds for your coffee. The downside is that it’s not fresh and may taste acidic or sour.

One way to get great flavor for your hot coffee, even if you plan to later turn it into iced coffee, is to brew it as hot as possible.

In a recent article, I break down which coffee makers make the hottest coffee. What really surprised me was just how much they vary in temperature compared to the temperatures coffee shops like Starbucks use.

Just click that link to read it on my site.

Does heating cold brew coffee increase acidity?

Yes. Heating cold brew coffee does increase acidity. When cold brew coffee is heated (or regular coffee reheated), compounds such as chlorogenic and quinic acid are released which do increase the acidity in the finished product.

So the best way to heat cold brew coffee is to add hot water to it rather than heating the coffee itself.

When you take on a different heating method, the science we mentioned earlier comes into play and can change the flavor of the beverage.

These acids are naturally occurring compounds in every coffee, but increasing the levels of them gives the coffee a more acidic flavor.

For this reason, heating the water instead of the coffee and adding it to the cold brew is much less likely to result in an acidic flavor.

Aside from using great coffee beans, another way to get the best flavor for your coffee, hot or iced, is by using a French Press.

The detractors say it’s time-consuming and doesn’t make big enough batches.

But the purists swear by them and won’t use anything else. In a recent article, I break down both sides and examine whether or not a French Press is worth it.

Just click that link to read it on my site.

Is it okay to heat an iced coffee – and is that different than heating a cold brew?

Heating iced coffee is fine. However, as this will be the 2nd time the coffee has been heated (since it was brewed hot), it will be more acidic, more bitter, and sour than it tasted originally. Since cold brew coffee was brewed with cold or room temperature water it will naturally be less acidic.

So by heating iced coffee, you are just returning it to its original state before you added the ice. The difference here is that hot brewed coffee (the base of iced coffee) is not concentrated like cold-brewed coffee is.

What that means is that the recommended way to heat your cold brew coffee will not work as well for heating iced coffee. Unless you are looking for an incredibly weak cup of coffee, you will not want to add any excess water to your iced coffee.

The best way to heat iced coffee is either on the stove or in the microwave.

The stove on a low-heat setting is your best bet. However, you do run the risk of burning it, so you will need to be attentive.

Can I heat cold brew coffee in the microwave?

While it is possible to heat cold brew coffee in the microwave, it is not recommended as it will significantly and negatively alter the flavor. It would be far better to heat it on the stovetop and the best way is to add hot water to the cold brew.

Microwaves are a popular way to heat leftovers. For coffee lovers, not so much.

But if you’re adding hot water to your cold brew and you want to use the microwave to heat that water, go for it! Heating or reheating coffee always impacts the flavor. And in my humble opinion, the microwave has the worst results on the flavor of coffee.

And let’s face it. If you wanted crappy coffee, you’d have Folger’s Crystals. Since you likely have a quality bottle of cold brew and just want it hot, take the extra few minutes to do it justice.

How does cold brew concentrate differ from regular cold brew?

Cold brew coffee concentrate simply has a much larger ratio of coffee to water. For that reason, if you sometimes like to heat up cold brew coffee, it will result in a much better cup of coffee if you start with cold brew concentrate.

So start with cold brew concentrate and keep it cold.

Then add the recommended amount of water but heat it first. Get it hotter than you would want to drink it since when it mixes with the cold brew concentrate, it will naturally cool down.

Does the caffeine content change when cold brew gets heated?

Coffee and caffeine stay the same no matter what the temperature, and whether or not cold coffee gets heated or hot coffee gets iced.

Now if you’re using cold brew concentrate, you obviously can alter the caffeine content by using a higher ratio of concentrate to water. But it won’t change if you heat it up.

Is cold brew better than iced coffee?

As a general rule, cold brew coffee tastes better, smoother, and less acidic than iced coffee. This is because iced coffee is hot coffee that gets cooled down as opposed to coffee that is brewed with cold or room-temperature water.

So, the primary difference between cold brew and iced coffee is the way they’re brewed.

Cold brew coffee is brewed with either cold water or room-temperature water. The coffee grounds are soaked in the water for anywhere between twelve and forty-eight hours.

What you end up with is a much more concentrated coffee that is perfect for pouring over ice. Even as the ice cubes melt, your coffee won’t taste watered down.

It may even taste a bit too strong at first. Cold brew coffee is known for being slightly sweeter and milder in flavor. It is also known to pack a more intense buzz, as well.

And because the coffee and water sit in unison for more time, the caffeine concentration of cold brew is higher. On average, you can expect a cup of cold brew to have about ten to twenty more milligrams of caffeine than an iced coffee.

On the other hand, you brew iced coffee like any hot coffee. It is your typical hot coffee that is cooled down (time permitting) and then poured over ice.

One of the main benefits of iced coffee is convenience. For most people, it only takes about ten minutes to brew, or even just the touch of a button for those of us with machines. But the cold brewing method is the best way to get delicious coffee that is iced.

Of course, you will also need to take the cooldown time into account. However, the cooldown time differs depending on many different factors.

As for the flavor, iced coffee is known for having a bolder flavor profile than that of cold brew coffee.

You can add some taste to both types of coffee with milk, cream, sugar, flavored syrups, cinnamon, or any other condiments that you enjoy.

Final thoughts

In this article, we took an in-depth look into the world of cold brew coffee.

We explored how it differs from iced coffee, and answered the question can I heat up cold brew coffee? But we also explored the best ways to heat up cold brew while keeping the flavor and acidity intact.

Coffee connoisseurs swear by cold brew vs iced coffee. And they also take the time to get cold brew hot the right way and avoid that unpleasant bitter taste. And the best method for doing that is to add hot water to unheated cold brew concentrate.

If anyone is on the keto diet, you might be surprised to learn that you can drink cold brew, iced coffee, and even lattes from your favorite coffee shop and not blow your ketosis.

The key, which I break down in a recent article, is in knowing exactly how to order your drinks. Just click that link to read my complete guide on my site.

Jeff Campbell


Saturday 5th of December 2020

Dear Jeff,

I have question for cold brew coffee. How can i preserve the milky cold brew + fresh milk coffee taste if i want to courier to my friend that need to take 1-2 days to get to them? Can it stand for 1-2days during the delivery by the courier service? Or can i have it in the sealed glass bottle and UHT? Hope to hear from you soon. Thank you.

Cheers, Jimmy

Jeff Campbell

Tuesday 8th of December 2020

Hi Jimmy

Coffee is all about freshness, so once brewed, it starts to go stale. Starbucks and others who package cold brew for sale are pasteurizing it to lock in freshness. You could do that too by doing it home canning style. But I'd be concerned about adding milk to that and then taking 1-2 days presumably at room temperature to get to your friend before drinking.

So if I had to mail or courier cold brew, I would just do the coffee itself, in some sort of airtight container, and I would pack it as soon as it was done brewing and ship immediately.

Hope that helps!