A few days ago, I was having some friends (Frank and Maurice) over at my house for a brainstorming session. We periodically have these kinds of sessions but it was the first time that a sitting was happening at my house.
We take a lot of coffee during our meetings, so I had to make my Chemex gear ready. That was when I noticed that I had only two Chemex filters remaining. Well, I knew that I could get a couple of generic filter papers from the grocery store and I was wondering if I could use the regular coffee filters in my Chemex.
I decided to test and compare regular filters to Chemex filters and have my friends observe and taste the different coffees.
Test Question: Can I use regular coffee filters in a Chemex?
The tests demonstrated that regular coffee filters are an undesirable choice for use in a Chemex because they yield a coffee that is dull and has a papery taste. The papery taste lingers on even after rinsing the filter before use. Regular paper filters also tend to break easily and drop the grounds into your coffee.
Regular filters have a lighter and lower grade of paper that allows water to filter through much quicker, causing under-extraction. Although you can correct this by increasing the grinds ratio, the filters also tend to tear and break apart leading to coffee grounds dropping into the carafe and muddying the coffee.
Using regular filters with Chemex is a sure way to degrade your coffee. The secret behind the superior coffee from a Chemex coffee maker is in the filter, hence the popular adage among Chemex lovers that “It ain’t a Chemex if the filter is not a Chemex filter”.
However, other pour-over and drip filters have proved to work perfectly in a Chemex and produce coffee that is of good quality.
Test: Chemex Filters vs Regular Filters
For this test, I used two Chemex filters in a side-by-side comparison to the results from two regular filters.
We agreed with my two friends that I would serve two cups of coffee, each cup from a different filter, to each one of us without me revealing the type of filters used. We also decided to have two coffee breaks in between the brainstorming sessions. I served two coffee cups to each one of us during break time.
Equipment and Materials
- 2 6-cup Chemex brewers
- A variable temperature electric kettle
- Burr Grinder
- 2 Chemex filters
- 2 generic paper filters
- A scale with a timer
- 6 coffee mugs; two for each one of us
- Coffee beans
- 2.5 liters of filtered water
- A straw
Testing Procedure
Number of tests: 2
Test 1
- Grind size medium-coarse
- Coffee ratio 60g to 1 liter
- Type of filter: 1 Chemex paper, 1 regular paper filter
Test 2
- Grind size medium-fine to medium
- Coffee ratio 40g to 1 liter
- Type of filter: 1 Chemex paper, 1 regular paper filter
Each test involved using one regular filter to make 3 cups of coffee and one Chemex filter to make 3 cups. I followed identical Chemex brewing steps for all the filters and carefully recorded apparent differences during the process.
Key Differences Between Regular Filters And Chemex Filters
There were noticeable differences in the structure, mass, and resistance to the grounds and water between the generic and Chemex papers. For example, the generic papers were lighter and thinner. This table highlights the differences during the brewing process.
| Regular Filter 1 | Chemex Filters 1 | Regular Filter 2 | Chemex Filter 2 | |
|---|---|---|---|---|
| 2 | Easily collapsed into the spout even after placing the three leaves directly on the spout | Remained robust and did not collapse or rip apart | We lined a straw against the spout to prevent it from collapsing | Showed no signs of collapsing |
| 3 | Was brewing fast before collapsing. Brewed very slow (8 minutes for 1 liter) after collapsing time | Brew time was about 5:10 minutes to brew 3 cups (1 liter) | Took 4:40 minutes to brew 1 liter | Took 7 minutes to brew due to the finer grind size |
| 4 | Broke apart and released the grounds into the carafe | Easy to remove it from the carafe | Almost broke apart when retrieving it from the decanter | Was still robust even after 7 minutes of brewing |
Every time I served the coffee, I recorded the comments of Frank, Maurice and myself as follows
| Ripped Regular Filter 1 | Regular Filter 2 | Chemex Filter 1 | Chemex Filter 2 | |
|---|---|---|---|---|
| Frank | -Very “dirty” coffee. | -Papery taste -Watery and flavorless | -Sweet and bright coffee -Has a great finish on the tongue | Clean but a little bit bitter |
| Maurice | -Muddy with a lot of sediments -A papery taste despite the presence of the sediments | -Sour and tea-like -Papery | -Delicious and clean | Some bitterness |
| Patrick (myself) | -Papery and muddy | -Weak coffee with a papery taste | -Clean, sweet and flavorful | Bitter and unpleasant |
Conclusion
I’d like to point out that the ‘dirty coffee’ comments were a result of the broken regular filter. When a filter collapses on the spout of a Chemex, it blocks air from leaving the Chemex and effectively stops or slows down the brewing process.
A prolonged extraction means that the generic filter stays wet for a longer period and is more likely to tear under the weight of the coffee grounds.
The generic coffee filters produced a coffee that was weak and papery. Their thin structure allows coffee to extract quicker. Adjusting the grind size and coffee ratio to prolong extraction increases the chances of the paper ripping apart especially when removing it from the Chemex jar
Coffee from the regular filter that did not break was very papery even though I had adequately rinsed out the paper before brewing. It was also weak and sour due to a much quicker extraction time. Excessive rinsing also weakens the paper.
Therefore, it is our view that regular filters are not favorable for use in a Chemex because they result in a weak and papery coffee and are likely to rip apart.
Why The Chemex Filters Are Superior To Regular Filters
Chemex filters have a special double-bonded paper that allows for optimal coffee extraction. Double bonding also ensures that the filter traps most of the oils, fats, bitterness, and sediments to give clean coffee that is rich, clean, flavorful, and has a good finish on the tongue.
The filters are also considerably heavier and more robust than regular filters and when placed correctly in the glass jar – the three leaves against the spout – they do not collapse into the spout.
Collapsing can interfere with the extraction process as it blocks air in the Chemex from escaping through the spout when coffee enters into the jar.
Commonly Asked Questions
Bleached Vs Unbleached Chemex Filters
Bleached and unbleached Chemex filters give the same results; clean and flavorful coffee. Bleached filters are oxidized to make them white whereas unbleached filters retain their natural brown color. Both filters undergo a series of baths with hot water to cleanse them.
Whether you are using a bleached Chemex filter or an unbleached one. It is essential to use hot water to pre-wet the filter before brewing to eliminate the papery taste.
Unbleached Chemex filters are compostable whereas environmental concerns have been raised with regard to bleached papers and filters.
Why Is Your Chemex Filter Clogged?
Clogging on a Chemex filter occurs when the coffee grounds are too fine. Clogging prolongs the extraction process and leads to over-extraction (bitter and empty coffee).
To eliminate clogging, adjust your grinder to a medium-coarse grind setting. Sea salt is an excellent example of the texture that your Chemex coffee grounds should resemble.
Chemex Square Filter vs Circle Filter
There is no significant difference between square and circle filters apart from the shape; they both brew similar coffee. However, some people observe that a circle filter sits flush on the mouth of the Chemex whereas others prefer the square-shaped because it sticks out of the Chemex and is easy to retrieve.
Is A Chemex Filter Reusable?
Ideally, a Chemex filter is a single-use filter and therefore not reusable. However, some people have reused these filters by softly brushing the coffee particles off of the paper, drying the filter, and using it a second time.
We do not recommend reusing Chemex paper filters because the paper absorbs oils that can alter its porosity and consequently impact the extraction when you reuse it. You also risk tearing and mildew due to the wet paper.
We tested and wrote an article about the best options for reusable or multiple-use filters for Chemex.
Can I Use Melitta #4 Filters In A Chemex
No. Using the Melitta filters in your Chemex is a sure way to make bad coffee. Melitta #4 filters collapse and break apart easily when pouring water on the grounds especially when brewing three or more cups.
You can get away with using these filters to make little amounts of coffee but the risk of muddying your coffee remains high.
Instead, we recommend that you use reliable and tested cheaper alternatives to Chemex filters for your Chemex.
