Chemex coffee makers

What Is a Chemex Coffee Maker?

The History and Iconic Design of the Chemex

The Chemex coffee maker was invented in 1941 by German-born chemist Peter Schlumbohm. Its distinctive hourglass-shaped design has since become an icon of coffee culture and is represented in the collection of the Museum of Modern Art in New York.

But the Chemex is much more than a design object. Its brewing system was created to produce an exceptionally clean and clear cup through pour-over coffee extraction. Combined with its characteristic paper filters, the Chemex has become one of the most recognisable manual coffee makers in the world.

Why Is the Chemex Made from Borosilicate Glass?

The classic Chemex coffee maker is made from non-porous borosilicate glass, a material particularly well suited to coffee brewing. It is designed to withstand temperature changes and does not readily retain odours or flavours between preparations when properly cleaned.

This makes it an excellent material for tasting specialty coffee, allowing the aromatic characteristics of the coffee to remain at the centre of the experience.

Different Chemex Coffee Maker Sizes: Which One Should You Choose?

Chemex coffee makers are available in several sizes. Choosing the right capacity depends primarily on how much coffee you usually prepare and how many people you want to serve.

Capacity figures can vary slightly depending on the specific Chemex model and the manufacturer's definition of a cup, so always check the stated volume before choosing your coffee maker.

Chemex Filters: Paper or Reusable?

The Chemex filter plays a major role in determining the texture, clarity and flavour profile of the finished coffee.

Chemex Paper Filters: Benefits and How to Use Them

Chemex paper filters are thicker than many conventional pour-over filters. They retain a significant proportion of coffee oils and fine particles, producing the exceptionally clean and clear cup for which the Chemex is known.

This clarity should not be confused with a lack of flavour. With the right coffee and recipe, Chemex brewing can highlight delicate floral, fruity and complex aromatic characteristics with remarkable precision.

Reusable Metal Filters: An Alternative to Paper

A reusable metal filter, such as the Able Kone, creates a noticeably different cup. More coffee oils and fine particles can pass through the filter, generally producing greater body and texture than traditional Chemex paper filtration.

A reusable filter also eliminates the need for disposable paper filters, although it requires regular and thorough cleaning to prevent coffee oils from accumulating.

Cloth Filters: Another Reusable Option

Cloth coffee filters provide another alternative, potentially creating a cup that sits somewhere between the clarity of paper and the fuller texture associated with metal filtration.

They require careful maintenance, however. The filter should be rinsed thoroughly after use and stored according to the manufacturer's recommendations to keep it clean and prevent unwanted flavours.

How to Make Coffee with a Chemex Step by Step

What Equipment Do You Need?

To prepare Chemex coffee consistently, you will need:

• A Chemex coffee maker
• A compatible paper or reusable filter
• A gooseneck kettle for controlled pouring
• A coffee scale
• A coffee grinder with adjustable grind settings
• Fresh coffee beans

A scale is particularly useful because it allows you to reproduce the same coffee-to-water ratio from one brew to the next.

Chemex Recipe: Coffee Dose, Grind Size and Pouring Technique

A useful starting point is approximately 60 g of coffee per litre of water. For Chemex brewing, a medium to medium-coarse grind is generally appropriate, although the ideal setting depends on the dose, filter and total brewing time.

1. Place the filter in the Chemex and rinse it with hot water to remove any paper taste and preheat the brewer.
2. Discard the rinse water and add the freshly ground coffee.
3. Pour enough water to saturate the grounds evenly and allow the coffee to bloom for approximately 30–45 seconds.
4. Continue pouring gradually in controlled circular movements.
5. Allow the water to pass naturally through the coffee without pressing or disturbing the filter excessively.

Water Quality and Temperature for Chemex Coffee

Water plays an essential role in coffee extraction. Water that is excessively hard or strongly chlorinated can affect flavour, while water with extremely low mineral content may also produce a less balanced extraction.

Clean, pleasant-tasting water with an appropriate mineral composition is therefore a good starting point.

For many coffees, a water temperature of approximately 90–96°C works well. The ideal temperature can vary according to the coffee, roast profile and recipe, so use this range as a starting point rather than an absolute rule.

How Long Should a Chemex Brew Take?

A total brewing time of approximately 3½ to 5 minutes can be a useful starting point for many Chemex recipes, although larger brews may naturally take longer.

If the water flows through much too quickly and the coffee tastes weak or sour, try a slightly finer grind. If the drawdown is excessively slow and the cup tastes bitter, dry or astringent, try grinding slightly coarser.

Ultimately, taste should guide your adjustments rather than brewing time alone.

Which Coffee Should You Choose for Chemex Brewing?

Whole Bean or Ground Coffee?

Whole bean coffee gives you greater control over freshness and grind size. Grinding immediately before brewing helps preserve aromatic compounds and allows you to adjust the grind precisely for your Chemex recipe.

Ground coffee can also produce excellent results when it is fresh and ground appropriately for the brewing method, but whole beans provide greater flexibility for adjusting extraction.

What Grind Size Is Best for a Chemex?

A medium to medium-coarse grind is generally a good starting point for Chemex brewing. The exact setting should then be adjusted according to your coffee dose, filter, brewing time and taste.

If the grind is too fine, water may flow too slowly and increase extraction. If it is too coarse, the water may pass through too quickly and leave the coffee under-extracted.

Which Coffee Origins and Roast Profiles Work Well with a Chemex?

Specialty Arabica coffees with distinctive fruity, floral or complex profiles can perform particularly well with Chemex brewing because the paper filtration produces a clean and transparent cup.

Ethiopian coffees may reveal floral and fruit-driven characteristics, while washed coffees from Guatemala or other Central and South American origins can offer excellent clarity, sweetness and structure.

Light to medium roast profiles are particularly popular for this brewing method because they can preserve much of the coffee's origin-driven character. However, there is no rule preventing darker coffees from being prepared in a Chemex if that is the flavour profile you enjoy.

Chemex vs Other Manual Coffee Makers: What's the Difference?

Each manual coffee brewing method creates a different sensory experience. The Chemex is particularly known for clarity, while methods such as the French press retain more oils and fine particles and therefore produce greater body.

The thicker paper filtration traditionally associated with the Chemex retains more oils and fine particles than many other brewing methods. This contributes to its characteristic clarity and can make delicate fruity and floral characteristics particularly easy to distinguish.

How to Clean and Maintain a Chemex Coffee Maker

Proper Chemex cleaning and maintenance helps prevent coffee oils and mineral deposits from affecting future brews.

After each use, remove the filter and coffee grounds and rinse the brewer thoroughly with warm water. Depending on the model and manufacturer's instructions, a mild detergent can also be used for a more thorough clean.

If mineral deposits appear, periodic descaling may be useful. The frequency depends primarily on the hardness of your water and how often you use the Chemex rather than on a fixed monthly schedule.

If you use a reusable metal filter, rinse it thoroughly after every brew and clean it regularly according to the manufacturer's instructions to prevent coffee oils from building up.

How Does Water Affect Chemex Coffee?

Water Hardness and Coffee Extraction

Water is one of the most important ingredients in Chemex coffee. Its mineral composition influences extraction and can significantly affect sweetness, acidity, body and aromatic clarity.

Very hard water may make some coffees taste muted or unbalanced, while water with extremely low mineral content can also produce disappointing extraction. The goal is not simply to use the “purest” possible water, but water with a balanced mineral composition that tastes pleasant on its own.

Filtered, Bottled or Tap Water: Which Is Best for Chemex?

There is no single type of water that works perfectly for every coffee. Filtered water can be useful when tap water has a strong chlorine taste or unsuitable mineral composition.

Some bottled waters can also work well for coffee brewing, provided their mineral content is appropriate. If your tap water already tastes clean and pleasant, it may also produce excellent results.

Rather than relying on one specific brand or a rigid TDS figure, experiment with your water alongside grind size, temperature and brewing ratio to find the combination that best reveals your coffee.

What Is the Best Water Temperature for Chemex Coffee?

There is no single perfect temperature for every Chemex coffee. A range of approximately 90–96°C is a useful starting point for many specialty coffees.

Lighter roasts may respond well to temperatures towards the higher end of the range, while darker or more soluble coffees may benefit from slightly cooler water.

Rather than focusing on an exact temperature such as 93°C for every coffee, adjust the temperature alongside grind size, brewing time and ratio according to the result in the cup.