Why Japanese Coffee Lovers Prefer Flannel Filters Over Paper

 When it comes to flannel filters, many coffee lovers may have only seen them in Japanese movies or through videos by Japanese baristas. Compared with the common paper filter and dripper combo, the flannel filter is far less popular outside of Japan. Most people’s first encounter with it comes from Japanese coffee culture itself.

That naturally raises the question: why do Japanese people love brewing coffee with a piece of flannel cloth? What makes coffee brewed with flannel so different from coffee filtered through paper?

What’s Special About Flannel Filters?

If you’ve read my posts before, you’ve probably seen me mention this: flannel filters produce coffee that’s richer and more aromatic. The reason is simple — flannel doesn’t filter out oils and insoluble compounds as thoroughly as paper does.

Flannel is a soft, fuzzy fabric that originated in Wales, England. Since its invention, it’s been used in countless applications thanks to its versatility. As a coffee filtration tool, flannel can actually be traced back to the 17th century — before paper filters even existed. At that time, people in Europe used flannel cloth to strain brewed coffee. However, it wasn’t until hand-brewed coffee spread to Japan that flannel filters were truly adopted as a brewing tool rather than just a strainer.

Compared to paper filters, flannel has larger fiber gaps, which allow coffee oils and fine insolubles to pass through. Coffee oils contain fat-soluble aromatic compounds that give the brew a fuller, richer fragrance. Those oils and insolubles also enhance the body, making the coffee feel smoother and more rounded on the palate. That’s the main reason flannel-brewed coffee is so beloved.

Flannel Filter Types and How They’re Used

A flannel filter typically has two sides — one fuzzy (the “nap” side) and one woven (the “cotton” side). The nap feels soft and smooth to the touch, while the cotton side feels slightly coarse due to the weave texture.

Both sides can be used to hold coffee grounds, but most people — myself included — prefer to place the cotton side inside and keep the fuzzy nap side facing outward. Why? Because coffee grounds tend to cling to the nap, making cleaning much more difficult.

Flannel filters are usually attached to a special metal handle. You can hold it in your hand while pouring, or hang it directly over a server like a regular dripper. Most people choose the latter for both the convenience and the ritualistic charm it brings.

How to Brew Great Coffee with a Flannel Filter

Brewing with flannel isn’t much different from using a dripper and paper filter in terms of parameters. However, if you’re hand-holding the flannel rather than placing it on a server, you’ll need to adjust from a coffee-to-water ratio to a coffee-to-liquid ratio, since the scale only measures the liquid dripping out of the cloth.

When using a flannel filter, I prefer deep-roasted beans, as the characteristics of flannel naturally complement darker roasts. For this example, I used a deeply roasted Sumatra PWN Golden Mandheling.

Brewing parameters:

• Coffee dose: 20g

• Coffee-to-liquid ratio: 1:13 (equivalent to 1:15 coffee-to-water)

• Water temperature: 88°C (190°F)

• Grind size: EK43 at 10.5, with 70–75% passing a 20-mesh sieve (a bit finer than usual hand pour)

• Pouring method: three-stage pour

Since we can’t see the total water volume when using flannel, the bloom stage is done simply by wetting all the grounds — not by adding double the coffee weight as usual. Start by pouring hot water into the center, then slowly move outward in circles until all grounds are evenly wet. This prevents channeling. Let it bloom for 30 seconds.

After blooming, pour with a steady stream, slowly spiraling from the center outward and back in again, repeating the motion until the water level nearly covers the coffee bed. Wait for it to draw down before starting the next pour.

During the third pour, focus your flow on the center of the bed, keeping your pouring circle within the size of a coin. Once you reach your target yield — in this case 260ml (based on 20g coffee and a 1:13 ratio) — remove the filter and stop pouring. Total brew time: 2 minutes and 21 seconds.

Comparing Flannel and Paper Filter Brews

I also brewed the same coffee using a Kono dripper with paper filter, under the same parameters, to compare. The flannel-brewed cup was noticeably more aromatic, smoother in texture, and had a longer aftertaste — though the differences were subtle unless tasted side by side.

Flavor-wise, both cups expressed the Mandheling’s signature notes of chocolate, nuts, pinewood, and spice, but the paper-filtered version was cleaner, while the flannel version offered a fuller body and deeper richness.

Why Flannel Isn’t Commonly Used in Cafés

You might be wondering — if flannel can produce such wonderful results, why don’t more cafés use it?

The answer is simple: flannel filters aren’t disposable. They require thorough cleaning and sanitizing after each use to maintain quality and hygiene. Compared with paper filters that you can toss out after brewing, flannel takes significantly more effort to maintain.

That’s why even in Japan, many baristas and home brewers now prefer the convenience of paper filters.

Still, both methods have their strengths. Flannel gives you aroma and body; paper gives you clarity and cleanliness. There’s no absolute winner — it all comes down to personal taste and the kind of coffee experience you want.