Guide · French press
French press guide
The French press is full-immersion brewing at its simplest: coarse coffee and hot water steep together in a beaker, then a mesh plunger holds the grounds down while you pour. Four numbers do most of the work — ratio, grind, temperature and time.
How a French press works
A French press (also called a cafetière, press pot or coffee plunger) is a cylindrical beaker with a lid and a plunger that fits tightly in the cylinder. The plunger carries a fine stainless steel wire or nylon mesh filter. Coarsely ground coffee goes into the empty beaker, hot water is added, and after the steep the plunger is pushed down, holding the grounds at the bottom while the coffee is served.
The mesh normally does not squeeze the grounds: most designs leave about 30 mm (1 in) of space below the piston at its lowest position. Because the filter is metal or nylon mesh rather than paper, more of the coffee's oils and fine particles reach the cup — which is also why the press comes up in research on cafestol (see below).
- Plunger knob — push down slowly after the steep.
- Lid — fits over the beaker and guides the plunger rod.
- Plunger rod — carries the filter assembly.
- Mesh filter — fine stainless steel wire or nylon mesh, shown at its lowest position.
- Brewed coffee — pour all of it out once plunged.
- Coarse grounds — held below the filter, roughly the texture of cooking salt.
- Space below the piston — about 30 mm (1 in) in most designs, so the grounds are held, not pressed.
The recipe card
| Variable | Starting point | Source note |
|---|---|---|
| Coffee : water | 30 g : 500 ml (≈1:16.7) | "about 30 g per 500 ml, more or less to taste" |
| SCA reference strength | 55 g per liter ± 10% | SCA brewing best practice (≈1:18) |
| Grind | Coarse | "about the consistency of cooking salt" |
| Water temperature | 93–96°C (199–205°F) | SCA target: 200°F ± 5° (93°C ± 3°) |
| Steep | ≈4 min | "some writers" give about four minutes |
| SCA contact time, coarse grind | 6–8 min | SCA's general guide for coarse grinds |
The two steep figures are not a contradiction: four minutes is the commonly cited French press time, while the SCA's 6–8 minutes is its general contact-time band for any coarse grind. Start at four minutes and lengthen the steep if the cup tastes thin.
Scaling to your press
Calculated from the two sourced ratios, treating 1 ml of water as about 1 g. For any other size, use the ratio calculator.
| Water | Coffee at 30 g / 500 ml | Coffee at SCA 55 g/L |
|---|---|---|
| 250 g | 15 g | 13.8 g |
| 350 g | 21 g | 19.3 g |
| 500 g | 30 g | 27.5 g |
| 1000 g | 60 g | 55 g |
Step by step
- Heat the water to 93–96°C (199–205°F), just off the boil. At altitude, check the water guide.
- Weigh and grind the coffee coarse. The grind chart places the press at the coarse end.
- Add the grounds to the empty beaker and set it on a scale.
- Pour in the water to your target weight and start a timer.
- Cover with the lid, plunger raised, and steep for about 4 minutes.
- Plunge slowly. A slow, steady push avoids splashing hot coffee on yourself; it is also said to maximize extraction of oils and flavonoids.
- Pour it all out. Coffee left in the beaker with the grounds can turn astringent and bitter, so serve it right away or move it to another vessel.
- 0:00 — pour 93–96°C water over the coarse grounds; start the timer.
- Steep — lid on, plunger up, nothing to do.
- ≈4:00 — plunge slowly, then pour out all the coffee.
- 6–8 min (dashed band) — the SCA's general contact-time range for coarse grinds; a longer steep to try if four minutes tastes weak.
Troubleshooting
| What you notice | Likely cause | Change |
|---|---|---|
| Bitter, harsh cup | Grind too fine for a long steep (over-extraction) | Grind coarser |
| Bitter by the second cup | Coffee left sitting on the grounds after plunging | Pour out everything right after plunging |
| Weak, thin cup | Grind too coarse | Grind finer, use more coffee, or steep longer |
| Plunger very hard to push | Fine grounds have low permeability | Grind coarser; do not force it |
| Grit or silt in the cup | Fine particles seep through or around the mesh | Grind coarser and more evenly |
| Hot coffee splashes up | Plunging too fast | Plunge slowly and steadily |
Change one variable per brew and note the result. The recipe sheet has a simple format for keeping notes.
A note on cafestol
Coffee beans contain diterpenes, chiefly cafestol and kahweol. Harvard's Nutrition Source says unfiltered coffee, such as French press and Turkish coffee, contains diterpenes that can raise LDL ("bad") cholesterol and triglycerides; espresso contains moderate amounts; and filtered (drip) and instant coffee contain almost no diterpenes, because filtering and processing remove them.
- How much reaches the cup: a University of Nottingham study measured an average of 603 mg of cafestol per 100 g of roast and ground coffee. French press, Turkish and boiled preparations gave the highest cafestol concentrations; the highest extraction yields were for the lightest roast brewed by French press (6.5%) or boiling (5.84%).
- What a paper filter does: in a 2017 study of paper-filtered coffee, 87.45% of the cafestol stayed in the spent grounds, 12.41% was retained by the paper filter and 0.15% reached the brew.
- Effect in a trial: in a six-month randomized trial in 46 healthy adults drinking about 0.9 liters (five to six strong cups) a day, cafetière coffee raised LDL cholesterol by 9–14%, and the liver enzyme ALT rose relative to the filtered-coffee group. The authors report that all increases were reversible once the intervention stopped.
This is a summary of published research, not medical advice. Anyone with questions about cholesterol and coffee should read the linked studies and speak with their own clinician.
A short history
Early versions go back to 1852, when Jacques-Victor Delforge and Henri-Otto Mayer patented a forerunner in France that did not seal around the filter. A patent by Marcel-Pierre Paquet dit Jolbert was published in 1924; Milanese designers Giulio Moneta and Attilio Calimani made a press with a spring seal that was patented in the US in 1929; and Faliero Bondanini patented his own version in 1958. The British and Irish name, cafetière, comes from the French for "coffee maker."
Checklist
- Scale and timer ready
- Coffee weighed: about 30 g per 500 ml (or 55 g per liter)
- Ground coarse, like cooking salt
- Water at 93–96°C (199–205°F)
- Lid on, plunger up, timer at about 4 minutes
- Plunge slowly
- Pour out all the coffee right away
Lab tip: the press is the easiest brewer to repeat exactly — same dose, same water weight, same timer. Once a cup tastes right, change only the grind or the steep, never both at once.
Sources
- Wikipedia — French press (ratio, grind, temperature, steep time, mesh filter, history)
- Wikipedia — Coffee preparation (grind vs contact time, leaving coffee in the press)
- Specialty Coffee Association — Protocols & Best Practices (55 g/L, 200°F ± 5°, contact time by grind)
- Harvard T.H. Chan School of Public Health — The Nutrition Source: Coffee (diterpenes in unfiltered coffee)
- Urgert R. et al. (1996) Comparison of effect of cafetière and filtered coffee on serum concentrations of liver aminotransferases and lipids: six month randomised controlled trial. BMJ 313:1362–1366 (PubMed Central)
- Zhang C., Linforth R.S.T., Fisk I.D. (2012) Cafestol extraction yield from different coffee brew mechanisms. Food Research International 49(1) (University of Nottingham repository)
- Rendón M.Y., dos Santos Scholz M.B., Bragagnolo N. (2017) Is cafestol retained on the paper filter in the preparation of filter coffee? Food Research International 100:798–803 (FAO AGRIS record)