What Kind of Coffee Should You Use in a Chemex?

While you can use any coffee variety and roast level you want in your Chemex, I’ve found that sticking to light and medium roasts and origins that have fruit-forward, bright flavor profiles tend to be best. Understanding how to use a Chemex and perfecting your technique and recipe are important, but choosing the right kind of coffee for Chemex is also important.

In this guide, I’ll explain how to pick the best coffee beans for Chemex brewing to elevate your mornings and suit your personal taste.

Can You Use Any Coffee in a Chemex?

The short answer is yes: you can use any coffee roast profile or origin that suits your taste preferences in a Chemex. However, I personally tend to gravitate towards light and medium roasts when I brew with my Chemex. Here’s why:

Light roasts spend less time in the roaster, usually between 8 and 10 minutes, so the insides of the beans only reach between 380 and 400 degrees (F), in most cases. This short roast time prevents the breakdown of organic acids and sucrose molecules that contribute bright, fruit-forward flavors.

As a result, light roasts retain high levels of these compounds for a complex, nuanced flavor profile with notes of the following:

Berries
Citrus
Stone fruit
Flowers
Black tea
Vanilla
Dried fruit

The Chemex’s thick paper filters complement these flavors by removing bitter oils while allowing the fruity brightness and acidity to shine through.

Medium roasts are roasted slightly longer and reach higher internal bean temperatures, between 10 and 13 minutes and 400 to 430 degrees (F). This additional roasting develops some of the sugars into caramelized flavors while still maintaining enough acidity for balance.

Dark roasts stay in the roaster for 13 to 16 minutes and hit internal temperatures above 430 degrees (F). At that temperature, most of the compounds that contribute to fruitiness and bright acidity get denatured, and a large portion of the sugars are caramelized. As a result, you get deep, dark flavors, like chocolate, hazelnut, molasses, pepper, and tobacco.

Chemex brewing highlights the lighter, brighter, fruitier, and more acidic flavors in coffee. So while you can use any bean in a Chemex, I find light and medium roasts to be ideal for highlighting the coffee’s inherent qualities.

Let’s take a closer look at how different roast levels and bean origins fare in the Chemex brewer.

Light Roast Coffee in a Chemex

Lightly roasted coffee beans (also called City or City+ roast) contain higher levels of organic acids like malic, citric, and chlorogenic acids. Malic acid has an apple-like tartness, citric acid provides a bright lemon and grapefruit flavor, and chlorogenic acids impart a green, vegetal quality. These lively acids are very sensitive to heat and degrade quickly during roasting. Light roasts lasting 8 to 10 minutes at lower temperatures retain much of these compounds to provide juicy, fruity flavors like berry, citrus, and stone fruit.

Light roasts also have higher levels of sucrose, a disaccharide sugar that breaks down into simple sugars like glucose and fructose during roasting. In light roasts, most of the sucrose remains intact, providing a honey-like sweetness and floral aromas. As roasting progresses, sucrose caramelizes into richer, darker flavors. But light roasts highlight sucrose’s delicate sweetness.

When brewed in the Chemex, light roast coffee’s acidity and aromatics shine through brilliantly. The thick paper filters remove most of the natural coffee oils holding bitter, astringent compounds. This allows the fruity brightness and sweetness to take center stage. You’ll taste clean, nuanced flavors like lemon, peach, honeysuckle, and orange blossom. The Chemex’s propensity to highlight a light roast coffee’s inherent qualities makes it an excellent pairing in my opinion.

Some of my favorite light roast coffees for Chemex include the following (these also work well in other pour over apparatuses, like the Hario V60):

Rwanda Gashonga: Tart citrus and stone fruit notes like strawberry and lemon.
Ethiopia Guji: A complex symphony of berries, orange, and floral aromas like jasmine and lemongrass.
Costa Rica Tarrazu: Sweet lime acidity with crisp flavors of apple, honeydew melon, and nectarine.

Medium Roast Coffee in a Chemex

Medium roasts, sometimes labeled Full City or Full City+, offer a harmonious balance of acidity, sweetness, and body. Beans are roasted between 10 and 13 minutes and reach higher temperatures between 400 and 430 degrees (F). This additional heat begins caramelizing the sugars while degrading some of the organic acids.

The sucrose breaks down into simple sugars that undergo the Maillard reaction. This creates richer flavors like chocolate, hazelnut, almond, and toasted bread. Meanwhile, acids like citric and malic degrade into acetic acid, which has a vinegar-like pungency. The result is a coffee with well-developed roast character complementing fruity acidity.

In a Chemex, the medium roast’s layered profile shines through beautifully. The paper filter strips out the bitter oils for a silky mouthfeel, while still highlighting the bean’s origin character. You get the best of both worlds: fleeting fruitiness like berry and lime followed by chocolate, nut, and caramelized notes from the roast. This combination is complex and really enjoyable, in my opinion.

I suggest these tasty medium roasts for Chemex brewing:

Guatemala Huehuetenango: Milk chocolate sweetness with hints of strawberry and nectarine.
Sumatra Mandheling: Rich tobacco aromas balanced by bright stone fruit.
Peru Organic: Toffee and nutty flavors with just enough grapefruit acidity to keep it interesting.

Dark Roast Coffee in a Chemex

Dark roasts spend more time in the roaster, anywhere from 13 to 16 minutes and hit internal bean temperatures reaching over 430 degrees (F). This significantly degrades organic acids and caramelizes virtually all sugars into bittersweet, almost burnt flavors. The fruity origin character becomes eclipsed by an intense roast profile of charred wood, molasses, and smoke.

In my experience, dark roasts tend to underwhelm in a Chemex. The thick filter papers scrub out most of the oils that give dark roasts their signature richness and viscous mouthfeel. Very dark roasts can become one-dimensional, bitter, and overly drying without those oils since the tartness and fruitiness that the Chemex highlights are mostly lost during the extended roasting process.

However, dark roast devotees may disagree with me! If you prefer your coffee on the darker side, you can certainly try out a dark roast in your Chemex. Just keep in mind that the origin nuances will be very subtle at best. Look for beans with chocolate, nutty, or slightly smoky flavors to complement the extreme roast.

Some dark roasts to experiment with in your Chemex include the following:

Ethiopia Yirgacheffe Dub Gira: Blueberry and stone fruit notes darkened into molasses and cocoa flavors, with still some floral complexity.
Sulawesi Toarco Triple Pick: An Indonesian coffee with notes of spices, dark chocolate and subtle smokiness. The processing results in a smooth body despite the extreme roast.
Sumatra Mandheling: Very dark but with some herbal, earthy qualities that the Chemex can bring out nicely.

What Grind Size Is Ideal for Chemex Brewing?

The ideal grinder settings for Chemex brewing is medium-fine, around the texture of granulated table salt. You want the grounds to be small enough to extract properly within the short 4 to 6 minute brew time. But not so fine that the filter basket clogs and causes a slow drip and overextraction. A good target grind size is between 400-700 microns for particle diameter. I aim for around 550 microns.

It takes some dialing in and trial and error to find the ideal setting, but getting the grind size right makes a huge difference. Tweak the grind setting and taste the results as you hone in on that perfect extraction sweet spot.

Why Grind Size Matters for Chemex Brewing

Grind size is important for all brew methods, but especially critical for pour over. With immersion methods like French press, the coffee grounds steep in hot water for several minutes. This long brew time allows thorough extraction of flavors and oils regardless of grind inconsistencies.

But Chemex relies entirely on a quick, efficient pass of hot water through the coffee bed and filter. The flow rate, and thus the extraction, depends entirely on grind size (and gravity, but that’s a constant!). If the grounds are too fine, the filter clogs and the water flows at a crawl. This leads to overextraction and astringency. Too coarse, and the water races through without fully extracting sweetness and acids, leading to an undrinkably sour cup.

An ideal grind exposes all the coffee’s soluble components—sucrose, organic acids, lipids, and aromatics—to hot water for just the right amount of time, leading to a balanced cup of coffee.

With inconsistent grind sizes, you get uneven extraction. Ultra-fine powder overextracts, bringing out bitter tannins, while large particles under-extract and taste sour. But with uniform grounds, you can achieve harmonious sweetness, brightness, and aroma, all while maintaining that ideal brewing time.

Wrapping Up: Choosing the Best Coffee for Chemex Brewing

While you can use any coffee in a Chemex, light and medium roasts really shine, in my opinion. Their fruity, floral flavors are highlighted by the Chemex brewer, while darker roasted flavors become muted. A uniform grind allows you to dial in sweetness, acidity, and aromatics into perfect balance. Dark roasts often disappoint, so I tend to save them for espresso, cold brew, and French press coffee.

You might disagree, though, so experiment with different roasts and coffees to find your perfect match. Taste is subjective, so brew what you enjoy most. Hopefully these tips help you brew stellar Chemex coffee!

Frequently Asked Questions

What if I don’t have a burr grinder at home? Can I still use pre-ground coffee in my Chemex?

You can use pre-ground coffee in a pinch, but it’s not ideal. Without a burr grinder to grind each batch freshly, you can’t customize the grind size. And pre-ground coffee stales rapidly after grinding compared to whole beans. Avoid store-bought ground coffee, as it’s almost always ground for drip brewers and too coarse for a Chemex. For best results, I’d recommend either investing in a quality burr grinder, or grinding small batches at your local coffee shop just before brewing. With the right grind, even average beans can make great Chemex coffee.

Do I need a kitchen scale to brew Chemex coffee?

Using a digital kitchen scale to weigh your coffee and water is highly recommended for Chemex brewing. The standard Chemex ratio is around 1:15 or 1:16 coffee to water. Weighing ensures you nail this ratio every time for consistent results. It also allows you to adjust the strength of your brew if desired. A scale takes the guesswork out and helps you hone in on your favorite recipe.

How fine should I grind for Chemex?

The ideal grind size for Chemex brewing is between 400 and 700 microns, with 550 being a nice sweet spot for a balanced cup. The lower end of this range can produce a bit of bitterness because the finer grinds will slow down the flow of water, causing more extraction. The higher end can produce a little sourness, as the coarser grind size lets water flow more rapidly, potentially leading to underextraction. I recommend starting at 550 microns and adjusting your following batches for taste.

What’s the ideal water temperature for Chemex brewing?

Ideally, you should use water between 195 and 205° (F) for Chemex brewing. That range will prevent burning the grounds and adding bitterness, while also allowing for full extraction and complex flavor profiles. It’s a good idea to get a good gooseneck kettle for Chemex brewing, especially one that has an accurate thermometer to let you dial in those temperatures.