Also known as the coffee plunger, is probably the most underrated method of brewing coffee. It is cheap, easy, and repeatable.
With other methods of brewing coffee, the water passes through the grounds, with the french press, the water and coffee are steeped together which helps produce a more uniform extraction. Another relatively unique aspect of the French press is the way that it filters the grounds from the brewing liquid: by using a metal mesh. The holes in the mesh are relatively large so that more of the non-soluble material from the coffee gets into the cup. There are pros and cons to this, the advantage is you get little of the coffee oil and some tiny suspended pieces of coffee in the cup, which gives the brew a bigger, richer body and texture. The disadvantage is the silty particles of coffee sitting at the bottom of the cup, if accidentally drunk, it can give an unpleasant and sandy mouthfeel.
The Ratio
Recommended brewing ratio: 1:12, coffee-to-water ratio. So for a 12 oz cup of coffee, use 20~35g(1oz) of ground coffee.
The Grind
Many people grind their beans very coarsely when brewing in a French press, but it’s not necessary unless your grinder produces a lot of very fine pieces and your brews quickly turn bitter. Recommend a medium/fine grind size, resembling beach sand but not too powdery.
Steps to Brewing with a French Press
Grind the coffee beans just before you start brewing. Be sure to weigh the coffee first before grinding.
Boil a kettle or pot of fresh water sustainable for brewing coffee to about 198F(92C), hot but not quite boiling.
Put the ground coffee into the French press and place it on the scale.
With the French Press on the scale, pour in the amount of water desired. Pour relatively quickly in a thin stream over the grounds and make sure there’s no dry spots.
Gently stir the coffee with a wooden spoon or chopstick.
Leave the coffee to steep for 4 minutes. During the steeping process, the coffee will float to the top to form a crust-like layer.
There should be a little foam and some floating grounds remaining on the top. Use the spoon to scoop them off and discard them.
Place the metal mesh plunger in the top of the beaker and gently push the grounds down to the bottom of the pot. Ideally, the plunger will lower smoothly and gradually with 15 to 20 pounds of pressure. It should take 15 to 20 seconds to push the plunger to the bottom. If the plunger thunks to the bottom with almost no resistance, the grind is too coarse. If you have to strain to get the plunger to the bottom of the pot, the grind is too fine.
After pushing the plunger all the way, pour into a cup and enjoy.