Updated: Jul 12, 2020
French Press coffee is awesome, potent coffee, with more volatile aromatics and coffee oils than almost any other brew method. The reason is its mesh filter, which allows all these wonderful tastes and smells into your cup, while still filtering out most of the non-dissolving solids (the coffee mud).
In order for the filter to work well, we grind the coffee fairly coarsely, so that the larger coffee particles won’t be able to slip through the filter and into your cup.
If you think on a molecular level, having larger particles means that the overall surface area of the coffee is smaller, and so fewer coffee molecules are exposed to the water. Less exposure means that it takes longer for the water to penetrate the cell walls, and so it takes longer to extract the same amount of tastes and aromas than in other brew methods.
The temperature of the slurry has a great impact on the taste of the coffee. If the coffee’s too hot, it will have more bitter tastes, and if too cold, the coffee will have more of a sour taste. The challenge for this brew method is keeping the slurry hot enough over time to avoid souring. To achieve the goal temperature of an average of 206F/96C, before adding coffee, warm the jar and the filter with boiling water. After 20-30 seconds, dump the water and add coffee and just off boil water.
Seeing as it is the water that extracts the coffee’s tastes and aromas, it takes longer than some other brew methods to coax out the coffee oils and aromas. The standard is 4 minutes, but people commonly brew 5-6 minutes.
One other tip: because the water temperature of the slurry is so important, I recommend thoroughly pre-heating the FP with hot water (and dumping it) before adding the coffee. This can really improve the cup if you haven't done so until now.
Step by Step Instructions
Note: the procedure here is just an example - you can alter the order of some things here as you see fit.
For each cup you intend to make:
Boil more water than you'll need to brew your coffee.
Preheat your french press (both the brewing chamber and the filter) with some of the boiling water. Optionally, you can do the same with your cup(s) if you like your coffee really hot.
Measure out 1.5 - 2 heaping tablespoons per cup (250ml) of brewed coffee.
If grinding (hopefully), set your grinder for a coarse grind
Dump out the water.
Add the ground coffee.
Slowly pour in 250ml +- of "just off boil" water for each cup you're brewing.
If you're using fresh roasted and just-ground coffee, you may well experience the "bloom effect." A bloom is a chemical reaction that makes a little volcano in your french press. Use a large spoon to pat the coffee down (try not to stir) into the slurry, making sure that all the coffee is wet/submerged.
Place the filter just above the water line.
Wait about 4 minutes, then press the filter downwards gently and slowly. When you reach the bottom, pour and enjoy.