Quick Answer
Use 1 gram of coffee for every 15 grams of water, ground as coarse as flaky sea salt. Pour water at 92 to 94 degrees Celsius, let the grounds bloom for 30 seconds, top up to your total weight, and steep for a full 4 minutes before pressing.
Press the plunger down slowly and steadily, then decant every drop into a mug or thermal carafe. Leaving brewed coffee sitting on the grounds is the single biggest reason French press tastes bitter.
A 30 gram dose with 450 grams of water hits the sweet spot for two solid mugs.
The grind: coarse as sea salt
The mesh screen in a French press is much wider than a paper filter, so it cannot trap fine dust. If you use pre ground supermarket coffee or anything finer than table sugar, you get sediment in the cup and a bitter, over extracted finish.
Run whole beans through a burr grinder set to its coarsest setting. The grounds should look chunky, irregular, and flaky, similar to coarse sea salt or rough cornmeal. If your grinder only goes medium, the cup will still be drinkable, just expect a heavier mouthfeel.
The ratio: 1 to 15
Specialty coffee shops standardise on a 1:15 brewing ratio for immersion methods. It balances the bright acids in the bean against the heavier sugars without skewing either direction.
- 2 cup press: 20 g coffee to 300 g water.
- 4 cup press: 30 g coffee to 450 g water.
- 8 cup press: 60 g coffee to 900 g water.
A cheap digital kitchen scale is the single best upgrade you can make to your French press. Volume scoops drift wildly depending on grind size, while weight does not lie.
The water: just off the boil
Boiling water hits 100 degrees Celsius at sea level. Pouring it straight onto coffee scorches the grounds and pulls harsh, ashy notes into the cup. Bring the kettle to a full boil, take it off the heat, and wait 30 to 45 seconds. That puts the water between 92 and 94 degrees, the range every barista trainer points to for immersion brewing.
The bloom: 30 seconds
Pre warm the empty carafe with hot tap water and tip it out. Add the coffee, place the carafe on the scale, tare it to zero, then start a timer.
Pour just enough water to saturate every ground completely, roughly twice the weight of the coffee. For a 30 gram dose, that is about 60 grams of water. Wait 30 seconds. The grounds will swell, foam, and release a thick crust of carbon dioxide. This bloom phase opens the cells of the bean so the rest of the extraction runs cleanly.
The 4 minute steep
After the bloom, pour the remaining water in a steady spiral until the scale hits your target weight. Give the surface crust one gentle stir with a wooden or plastic spoon to break it up and let the grounds sink.
Slide the lid on with the plunger pulled all the way up. The lid traps heat without forcing extraction. Let the timer run to exactly 4 minutes from the moment you first added water.
The plunge and the pour
Press the plunger straight down with steady, even pressure. If you feel resistance, ease off rather than forcing it. A hard plunge pushes fine sediment around the edges of the mesh and stirs up the bitter bottom layer.
The instant the plunger hits the bed, pour every drop into a mug or a thermal carafe. Coffee left sitting on the grounds in the press keeps extracting and turns sour and astringent within five minutes.
Common French press mistakes
- Pre ground supermarket coffee. Too fine. Always grind coarser than drip.
- Boiling water poured straight in. Wait 45 seconds off the boil.
- Skipping the bloom. You lose body and clarity.
- Pressing too hard. Creates muddy sediment in the cup.
- Leaving the brew in the press. Decant immediately.
- Eyeballing the ratio. A scale costs less than a bag of beans and fixes most flavour issues.
Cleaning the press
Rinse the carafe and plunger after every brew. Once a week, unscrew the mesh stack and scrub the discs with hot soapy water to clear coffee oils that turn rancid. Glass carafes are dishwasher safe on the top rack, but the metal screen lasts longer with a hand wash.
Frequently asked questions
How long should coffee steep in a French press?
Four minutes total, including the 30 second bloom.
Can I use medium grind in a French press?
You can, but expect a heavier, siltier cup. Coarse grind is the cleaner option.
Why is my French press coffee bitter?
Usually one of three things: grind too fine, water too hot, or coffee left sitting on the grounds after brewing.
How many scoops of coffee for a 4 cup French press?
Roughly 30 grams, which is about 4 level tablespoons of whole bean coffee, with 450 grams of water.
