The cloth filter

History

Ukers dates to 1711 the appearance in France of steeping: the grounds are enclosed in a fustian bag, a cotton and linen fabric, over which boiling water is poured. The idea progresses slowly in England and America, where beans are still boiled (source 1). In 1763, Donmartin, a tinsmith in Paris, builds a flannel-bag coffee pot; Gaudet uses a cloth filter in 1820 (source 1).

England adopts around 1817 the biggin, an earthenware pot whose rim carries a flannel or muslin bag, so that any pot fitted with such a bag ends up being called that (source 1). In 1922, Ukers still finds the flannel bag in Cuba, where cold water is poured repeatedly over a fine grind to draw a very concentrated extract, and in the large urns of Austrian restaurants (source 1).

In the United States, the quarrel of cloth versus paper breaks out in 1917. Aborn, for the roasters' committee, defends cotton, an “ideal sanitary filter” because it contains no chemical; Robison replies that the muslin bag is “decidedly unsanitary” in restaurants, and Richheimer, inventor of the Tricolator, accuses the coffee fats retained by the cloth of turning rancid (source 2). The comparative tasting of the same year ranks cloth second, behind paper (source 2).

Japan has kept cloth under the name nel drip, from the English words for “flannel” and “drip.” Hario writes that its V60 was designed to recover with paper the taste of coffee filtered through cloth (source 3).

The motion

The Japanese flannel filter, as described by James Freeman, founder of Blue Bottle, is a cotton flannel bag stretched on a wire hoop, ten to twelve centimeters long. A lot of coffee goes in, 40 to 50 g for a half cup of about 10 cl, and the water is poured with a gooseneck kettle, very slowly, for five to seven minutes (source 4).

Upkeep makes the method. The American roasters' booklet of 1921 asks that a new bag be washed to remove the sizing, rinsed in cold water, because hot water “cooks” the stains, and kept submerged in cold water between uses, never allowed to dry, so that it does not sour (source 2). Aborn wanted a large bag, free on all sides, of a muslin neither too loose nor too heavy, a single pass of water and no stirring (source 2).

The settings

• Grindfine “like cornmeal” for the American muslin of 1917 (source 2); coarse for the Japanese flannel filter according to Freeman (source 4)
• Dose40 to 50 g for a half cup of about 10 cl, Freeman's testimony (source 4)
• Brew ratioabout 1:2 to 1:2.6 for the Japanese half cup, calculated from Freeman's testimony (source 4)
• Temperatureboiling water in the instructions of 1921 (source 2); “quite low” in the Japanese flannel filter, no figure (source 4)
• Time5 to 7 minutes of pouring in Japanese practice (source 4)
• Pressurenone: gravity alone

What it has going for it

• Cloth is washed and reused: no paper to buy or throw away.
• It flows fast: 18.1 mL per second for a V60 cloth filter, against 6 to 11 for the papers measured in the same setup (source 5).
• It holds back a large share of the diterpenes: boiled coffee passed through a cloth filter drops from 939 to 28 in the unit of the Swedish study, against 12 for a home-made paper-filtered coffee (source 6).
• It gives no paper taste, and Freeman describes a velvety texture that no other filter gives (source 4).

What is held against it

• Upkeep is heavy: rinsing, storage in cold water, never drying, and Gagné judges it far worse than metal for this reason (sources 2 and 5).
• The fats retained in the cloth turn rancid if the bag is poorly kept, a reproach made as early as 1917 (source 2).
• The cup is less limpid than with paper, by the admission of the muslin's own defenders in 1917 (source 2).
• Cloth lets more diterpenes through than paper, according to the Swedish measurements of 2025 (source 6).

What it gives in the cup

Cloth gives a thicker body than paper and a slightly less clear cup: Robison acknowledged in 1917 that muslin gives a “fairly clear” coffee, but not as clear as paper (source 2). Freeman describes in Japan a density and softness that he attributes to water that is not very hot and to the slow pour (source 4); this is testimony, not a measurement.

For the oils, the study by Orrje and colleagues gives the order of magnitude: cloth holds back most of the diterpenes of a boiled coffee, paper holds back even more (source 6). The unit published in the abstract, milligrams per liter, seems high compared with the other studies; only the ratio between the values is used here.

Anecdotes

• In 1916, the American roasters, divided, suspended publication of their conclusions on steeping until laboratory confirmation; their committee nonetheless published in 1917 a booklet that argues for cotton and revives the quarrel with the partisans of paper (source 2).

The sources for this sheet

1. William H. Ukers, All About Coffee, New York, 1922, ch. XXXIV (Donmartin 1763, biggin around 1817, Gaudet 1820), ch. XXXV (Cuba, Austria) and ch. XXXVI (1711) · online · primary
2. William H. Ukers, All About Coffee, New York, 1922, ch. XXXVI (Aborn, Coffee Grinding and Brewing, 1917; replies of Robison and Richheimer; Tea and Coffee Trade Journal test, 1917; Joint Coffee Trade Publicity Committee, Coffee and Coffee Making, 1921) · online · primary
3. Hario, “The origin of the V60” (according to the manufacturer), accessed October 21, 2026 · online · secondary
4. James Freeman, interview with Lynne Rossetto Kasper, “Patience, practice key to Nel drip coffee method,” The Splendid Table, December 12, 2012 (testimony) · online · secondary
5. Jonathan Gagné, “An in-depth analysis of coffee filters,” Coffee ad Astra, August 4, 2019 · online · secondary
6. E. Orrje, R. Fristedt, F. Rosqvist, R. Landberg, D. Iggman, “Cafestol and kahweol concentrations in workplace machine coffee compared with conventional brewing methods,” Nutrition, Metabolism and Cardiovascular Diseases, 35 (8), 2025, 103933, doi:10.1016/j.numecd.2025.103933 · online · primary · reading: abstract