The Vietnamese phin filter
A small perforated metal chamber, a press set on top, a lid: the phin, a Vietnamese word taken from the French “filtre,” sits on the glass and lets a very concentrated coffee fall, drop by drop. It is the everyday coffee tool in Vietnam, served black or over sweetened condensed milk.
How does the Vietnamese filter make coffee fall drop by drop?
Start the scene or choose a stage. The animation simplifies the mechanism; what follows gives the details and the available references.
A small perforated metal chamber rests on the glass by its plate. The coffee will fall directly into the cup.
Read the stages without animation
- The chamber on the glassA small perforated metal chamber rests on the glass by its plate. The coffee will fall directly into the cup.
- The pressA perforated disc, set on the grind, levels it and holds it in place. The grind does not float when the water arrives.
- Wet firstA little hot water wets the grind, which swells against the press. The bed tightens and will slow the water.
- Fill and closeWater is poured in, the lid is set on, and the water slowly passes through the tight bed. The coffee comes out drop by drop, very concentrated, in two to five minutes depending on the trials.
- In the glassThe coffee falls on the condensed milk, or into an empty glass to be drunk black. A small, strong cup, with a light sediment.
To remember: Little water, a lot of coffee, a tight bed under the press: the water passes slowly and the coffee comes out very concentrated.
In history: Late 19th century at the earliest, in French Indochina; the precise origin was not found.
Read the full article and its sources ↓History
Coffee arrived in Indochina with French colonization. Ukers dates the first cultivation trials to 1887, near Hanoi, with arabica seeds from Réunion; arabica proved poorly adapted, and hardier species were turned to, including canephora (source 1). Vietnam is today the world's leading producer of canephora (source 4).
No one knows when this filter appeared, and no scholarly study of its history was found. The most plausible kinship is De Belloy's French coffee pot, around 1800, in which boiling water passes through a grind held by a perforated grid, and the perforated tamper that Hadrot patented in 1806 (source 1). An online essay compares the four parts of the Vietnamese filter with these apparatuses and proposes seeing in its support plate an adaptation to the individual cup (source 2).
The same essay cites L'Éveil économique de l'Indochine of April 1922, which advises colonists to take on trips “this little coffee filter for one person,” the too fragile glass being advantageously replaced by aluminum (source 2). The quotation could not be re-read on Gallica, which was closed to requests on the day of the search. If it is exact, it dates to 1922 an individual glass filter that had moved to aluminum.
The filter is made today in aluminum, stainless steel or brass (source 3). A Brooklyn brand made a stainless steel model of it in 2019, which shows that the object now travels with Vietnamese coffee (source 3).
The motion
The filter has four parts: a lid, a perforated press, the chamber with a perforated bottom, and a plate that carries it on the glass (source 2). The grind goes into the chamber, the press is set on to level it, a little hot water is poured on to let the grind swell, then it is filled and closed (sources 2 and 3).
The coffee then falls by itself, in about five minutes for a small 12 cl cup, according to the 2019 report (source 3); the 2022 essay gets two minutes with 20 g of coffee and 100 g of water and a medium to coarse grind (source 2). The glass sometimes receives the condensed milk before the water, but many Vietnamese drink their coffee black, the cà phê đen, “black coffee” in Vietnamese (source 3).
The settings
- Grindnot standardized; medium to coarse in the source 2 trial
- Dose20 g of coffee per 100 g of water in the source 2 trial
- Brew ratio1:5, calculated from the source 2 trial; the author attributes to French percolation coffee pots, since 1806, a ratio of 1:3.5 to 1:4
- Temperaturenot documented in the sources read
- Timeabout 5 minutes (source 3); 2 minutes in the source 2 trial
- Pressurenone: gravity, under a press that is simply set on
What it has going for it
- The device is individual, with no paper or electricity, and sits on any glass.
- It is light and nearly unbreakable, which already made it a travel filter in 1922, according to the quotation reported (source 2).
- It gives, in little water, a concentrated coffee that stands up to condensed milk or ice.
What is held against it
- The holes let particles through: the 2022 essay finds some at the bottom of the cup (source 2).
- The flow cannot be seen under the lid, and the rate depends on how tightly the press is set and on the grind (source 2).
- The metal does not hold back oils the way paper does; no diterpene measurement specific to this filter was found, but coffees not filtered through paper contain markedly more (source 5).
- Aluminum conducts heat quickly, and the 2022 essay fears a colder drink than with stainless steel; this is the author's hypothesis, not a measurement (source 2).
What it gives in the cup
The cup is small, strong and loaded: little water, a lot of coffee, a metal filter that lets through some of the fines and oils (source 2). Hence a thick body and a light sediment, which sweetened condensed milk softens when served that way (source 3).
No published measurement of yield, concentration or diterpenes specific to this filter was found. The order of magnitude for coffees brewed through metal can be read in the general analyses by Gross and colleagues (source 5).
Anecdotes
- In 1922, Ukers already lists the Annamite word “ca-phe” in his list of names for coffee around the world (source 1).
The sources for this sheet
- William H. Ukers, All About Coffee, New York, 1922, ch. I (names of coffee), ch. XX (French Indochina) and ch. XXXIV (De Belloy, Hadrot) · online · primary
- Dat Nguyen-Trong, “History of Phin,” annotated online essay, December 30, 2022, citing L'Éveil économique de l'Indochine, April 1922 · online · secondary · reading: yes (the 1922 quotation not re-read)
- Howard Bryman, “Brooklyn's Nguyen Coffee Supply Puts Fresh Spin on Vietnamese Phin,” Daily Coffee News, October 22, 2019 · online · secondary
- International Trade Centre, The Coffee Guide, 4th edition, Geneva, 2021, ch. 3 (production by species) · online · primary
- G. Gross, E. Jaccaud, A. C. Huggett, “Analysis of the content of the diterpenes cafestol and kahweol in coffee brews,” Food and Chemical Toxicology, 35 (6), 1997, pp. 547-554, doi:10.1016/s0278-6915(96)00123-8 · online · primary · reading: abstract