Chemex Coffee Ratio: Full Guide

Chemex Coffee Ratio - Full Guide

To make the perfect cup of coffee, you need to be familiar with the ideal Chemex Coffee Ratio. Special attention should be paid to both the amount of coffee that is placed on the hilt and the amount of water that you will pour the coffee. 

Of course, it is essential not to forget the Chemex filters that will be used for the machine. 

It is advisable to use filters designed explicitly for Chemex, but you could also use a substitute.

It’s time to start making coffee 🙂


  1. Chemex: What Is It?
  2. What Makes Chemex Pour-Over Coffee Different from Other Coffee Makers?
  3. Do You Know Which Chemex Coffee Ratio Works Best?
  4. How To Adjust Your Chemex Ratios
  5. Chemex Ratio: Making The Right Chemex Recipe
  6. Tips For Brewing The Perfect Cup Of Chemex Coffee

Chemex: What Is It?

Chemex: What Is It?

In 1941, Peter Schlumbohm invented the Chemex coffeemaker. It is inspired by an Erlenmeyer flask made of non-porous glass. The design was pretty innovative – plastic equivalents develop cracks and fissures over time which can accommodate mineral deposits affecting the overall flavor. The Chemex filter, 30% thicker than ordinary filters, contributes to the fresh taste. A cup of coffee with no bitterness or sediment is the consequence of using a heavy-duty filter to remove excess fats or oils.

What Makes Chemex Pour-Over Coffee Different from Other Coffee Makers?

It’s essential to keep the brewing process as simple as possible, precisely what Chemex and other pour-over machines do. You’ll need two things to make this fantastic coffee. These are freshly ground coffee beans and water that has been processed using a burr grinder (hot or cold).

The Chemex’s hourglass-shaped carafe holds the coffee grounds in a filter. Filtration occurs when the water passes over the grounds, resulting in a concentrated coffee flavor. Voila!

The water removes the coffee oils and scents on its own time and pressure. This method produces a clear, satisfying, and consistent liquid. It naturally creates a more aromatic and tasty brew with a distinct scent. This machine is ideal for enthusiasts who seek out the subtleties and complexity of light-roasted coffees.

Do You Know Which Chemex Coffee Ratio Works Best?

Any coffee-brewing procedure requires careful attention to the coffee and water used since the Chemex coffee water ratio directly affects extraction. Adapting the Chemex brew ratio for a given brewing procedure ensures the optimum extraction by considering the process’s various factors and the general recommendations that apply to most brewing processes.

Using a Chemex coffee machine, you may need to adjust the Chemex pour-over ratio to keep the Chemex proportions.

Chemex Brew Ratio Range from 1:16 to 1:18

Between 1:16 and 1:18 is the ideal Chemex coffee water ratio for most drinks. According to this data, that’s around 16 to 18 milliliters of water per gram of coffee. Contrariwise, you should utilize 15.6-13.8 grams of water for every 250 grams of fluid consumed. If you’re using the imperial measurement, this means that for every 8 fluid ounces of water, you should use 0.5 ounces of coffee.

These ratios employ weight measurements rather than volume dimensions for estimating coffee and water for precision. Coffee beans have varying densities, leading to different quantities of coffee used to calculate volume. Consider the coffee beans’ varying densities and weigh them instead to avoid this problem.

The Best Ratio for the Chemex is 1:16.66

A Chemex brew ratio of 1:16 to 1:18 works well for most brewing methods, but some require a more precise balance within this range. Adjust the Chemex pour-over ratio to account for various factors, such as the brew method.

Some specialists recommend a Chemex brew ratio of 1:16.66. The extraction is reduced because this is at the lower end of the standard range. Because less water is utilized, the coffee beans yield fewer molecules.

The Chemex filter is necessary to keep the extraction level to a minimum. Due to the filter’s thickness, you should increase the brew time. The longer the brewing period, the greater the amount of caffeine extracted. An over-extraction and a harsh taste might develop if the other factors are not evaluated and adjusted correctly.

A lower Chemex coffee water ratio compensates for longer brew times induced by a larger filter. In addition, reducing the amount of water used minimizes the time it takes to brew (usually about seven minutes).

A Ratio of 1:16.66 Also Produces More Coffee Liquid

Using a ratio of 1:16.66 increases the cup’s body as an additional advantage. People who go from a French press to a Chemex like this feature, which is only an added bonus.

Using less water or, to put it another way, altering the Chemex proportions can improve the quality of your brew. By using less water to improve the coffee, fines, which may produce bitterness, are kept out of the final cup.

Use Fresh Coffee for Best Results

You’ll taste the Chemex coffee water ratio variances when brewing if you’re using freshly roasted, flavorful coffee. Try to find similar coffee if you want to feel that fantastic sip of joy every morning. This way, you will be more energetic and full of positive vibes.

How To Adjust Your Chemex Ratios

First and foremost, you have to be very careful with your brew time. If your coffee takes too long to filter, the grind is likely too fine, and the filter becomes clogged. Try a coarser grind with your burr grinder to speed things up. Similarly, if your coffee Chemex filters out too rapidly, it may benefit from a finer grind.

While the amount of time it takes to brew depends on the size of your coffee maker and how many cups you’re producing, the Chemex 6 cup brews in around four minutes. You can shorten the brew time after you’re happy with the results.

My Coffee is too Bitter or Harsh

This is most likely due to an over-extracted brew. Grind the coffee coarser and add water quickly to shorten the brewing time. Make sure you don’t disturb the coffee bed by moving or shaking it.

My Coffee is Too Sour or Thin

Your brew has been under-extracted if this is the case. Increase extraction by stirring your coffee bed a few times or use fine-ground coffee to slow down the brewing process.

Chemex Ratio: Making The Right Chemex Recipe

Pour-over coffee made with a Chemex is excellent to prepare if you follow a few basic procedures. You’ll need 34g of roasted coffee beans for the first step. Also, weigh 520g of filtered water.

Use filtered water to maintain the flavor of your coffee. After that, go through the following procedure:

  1. A pot should be filled with filtered water from the top to the brim. Use a gooseneck kettle that can tell you how hot the water is. The water should be heated to between 200 and 205oC.
  2. Then use a food scale to ensure 34g of coffee on hand. You may ground your coffee beans to a medium-coarse grind using an electric burr grinder. When finished, this should be roughly the size of a grain of kosher salt.
  3. Place a filter in your Chemex once the water has boiled. Pour a tiny quantity of water into the filter to moisten it. Set the water aside after this. Then, add the ground coffee to the Chemex and stir it around. Use the Chemex to check that the coffee grinds are evenly distributed throughout the vessel.
  4. The next step is to tare the Chemex by placing it on your food scale. If everything goes according to plan, the scale should read 0.
  5. Slowly pour in 70g of water in a circular motion on the side of the Chemex filter, and you’re done! Keep the coffee blooming after you’re finished.
  6. Pour the remaining water into the Chemex at this point. Make sure the Chemex does not overflow by allowing the water to drain.
  7. Once the water has passed through the Chemex, the coffee in the carafe should be hot. Remove the filter and throw it away. Perhaps it’s even compostable. Now you can savor your freshly brewed cup of coffee!

Tips For Brewing The Perfect Glass Of Chemex Coffee

Use a Scale

To get the proper amount of coffee, you need a high-quality coffee scale, even though it seems clear. Use a kitchen scale to weigh your coffee instead of measuring it by volume. The grams to tablespoons conversion isn’t exact, but you may use ordinary kitchen tablespoons to measure coffee grinds.

Brew Less Coffee

As a general rule, larger batches are more susceptible to errors. Slightly reducing the quantity of your pack may help you find an efficient brewing method, and then you may build on that.

Use Filtered Water

If you want the perfect cup of joy, start with good water. There is a distinct difference in coffee flavor between tap water and filtered water, even if you heat the water before pouring it into your cup of joe. Remember that a cup of coffee is 95% water?

“Softness” is the primary factor for water in coffee. Many associations define this as water with no odor or color, no chlorine, alkalinity of 40 ppm, a pH of 7.0, and calcium hardness of 50-175 ppm CaCO3. Sounds like high school chemistry to me. Isn’t that scary?

If you’re skimming for water free of chlorine and soft, then that’s what you’re looking for. The term “soft water” refers to water that has reduced mineral content. Water that doesn’t have any minerals is also not good because even a tiny amount of minerals helps the coffee taste better.

Tap water for your coffee is generally preferable to bottled or filtered water. Still, the quality of your local tap water can make a difference. Charcoal-filtered water is the most acceptable way to brew a cup of coffee. Suppose you’re serious about utilizing the right amount of moisture. In that case, you can use distilled or reverse-osmosis water with a mineral supplement.


What is the best ratio for Chemex?

Between 1:15 and 1:18 is the optimal Chemex ratio of water to coffee for most drinks. This is around 15-18 milliliters of water per 1 gram of coffee.

How much coffee do I need for 2 cups of Chemex for 2 people?

To make 2 cups of Chemex coffee, the quantity of the coffee grounds that you’ll need to use is about 34 grams and 510 grams of water (that’s 17.2 oz of water). This amount is calculated with the default ratio 1:15 (1 gram of coffee to 15 grams of water).

How much coffee do you put in a 6 cup Chemex?

For one cup of Chemex coffee are needed 17 grams of ground coffee. Thus, for six cups of Chemex, you will need 102 grams of ground coffee, and for each gram of coffee, you will have to use 15 grams of water. 

In conclusion, for preparing 6 cups of Chemex coffee, you will need 102 grams of coffee and 1530 grams of water.

If you have a smaller Chemex then you can divide the cups into and prepare the coffee three times.

Chemex Coffee Recipe

If you have never prepared Chemex coffee at home, now is your chance to try it. The Chemex Coffee recipe is straightforward, and the result is a perfect cup of joe.
Prep Time5 minutes
Active Time5 minutes
Author: Mariela Dimitrova


  • Chemex
  • Pouring Kettle
  • Chemex Filter
  • Digital Scale
  • Grinder


  • 34 grams Grounded Coffee
  • 510 grams Water (201-205° F)


  • Step 1: Use the digital scale and weigh 34 grams of grounded coffee.
    34 grams Grounded Coffee
  • Step 2: Fill the kettle with filtered water and boil it.
    510 grams Water (201-205° F)
  • Step 3: Put the filter on top of the Chemex and pour hot water with the kettle all over it. Please do not overdo it with water. The filter should only be slightly wet.
  • Step 4: Throw the water from the glass.
  • Step 5: Put the grounded coffee on the filter and level it.
    34 grams Grounded Coffee
  • Step 6: Start the timer and pour 260 grams of water within 30 seconds. Begin in the middle and then work out through concentric circles.
  • Step 7: Rest for 30 seconds and then pour 250 grams of water.
  • Step 8: Let the coffee drain for about 5 minutes. Enjoy.

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