Neal tells me that you’re interested in further details of the French press coffee technique that he uses. I can’t claim the technique is mine; I learned it from my friend James Hoffmann. James is a former World Barista Champion and has a wonderful blog covering all things coffee. James has a great video of the technique here.
I’m fairly certain that James learned of the technique from another World Barista Champion, Tim Wendelboe from Norway.
Here is the basic theory of the technique as I understand it:
1. The brewing ratio is critical. So using a scale to weigh the grounds and the water will make a remarkable difference to the consistency of your coffee. I like 70g of grounds per liter of water. My press pot will hold about 700g if water, so usage 49/50g of grounds to the hot water.
2. Grind size matters. For French press, the coffee should be ground coarse and have a uniform particle distribution (actually the distribution is trimodal, but that’s a tangent). Only burr grinders can achieve this. If you don’t have a decent burr grinder, have your beans ground for French Press by a reputable coffee shop. (BTW, I recently looked at good burr grinders for home use and can highly recommend the Baratza virtuoso preciso. A bit pricey, but really the only decent one IMO at an almost affordable price point.)
3. Keep the brewing time consistent. I use 4 minutes for the grind size I use and will adjust the brewing ratio to find the ideal strength for my cup of coffee. Grind size, brewing ratio, and brewing time all interact, so adjusting only the brewing ratio helps me from getting confused when I’m dialing things in for a new batch of beans.
4. I will usually not cover the press during the steeping. I like to allow the grounds to “bloom” as much as possible. Anything that prevents this tends to yield an uneven extraction from the cake of coffee.
5. Skimming makes an amazing difference. I was shocked just how big this difference was when I first tried it, but it makes sense. The basic French Press design allows a lot of the “fines” from the coffee to pass through the plunged screen. These fines continue to steep in the coffee, resulting in very over extracted coffee with a bitter taste and a muddy mouthfeel. By skimming the cake of swollen grounds before plunging, you’re throwing out a lot of these fines, so you end up with less overextraction and a cleaner mouthfeel.