French Press = Coarse
Cold Brewing = Coarse
Percolator = Coarse to Medium
Auto-Drip = Medium
Vacuum Pot = Medium to Fine
Moka Pot = Fine
Espresso Machine = Very Fine
Ibrik = As Fine As Possible
These different brewing methods differ only in how long the water stays in contact with the bean and how much surface area the water has to interact with. The coarser the grind, the longer it must remain in contact with the water. The finer the grind, the more quickly the essential elements (fragrance, aroma, flavor) are released. If ground too coarsely for the brewing method, there is not enough surface area resulting in under-extracted or weak coffee. If ground too finely for the brewing method, there is too much surface area resulting in over-extracted or bitter coffee (as well as the danger of plugging up your brewer).
You will find that the same roasted bean will express itself differently in different grinds and brew methods. It will also taste different depending on how long it has stayed in the ground state. When you break down a roasted bean and expose it’s surface area you make it vulnerable to oxygen and moisture. The bean begins to lose its aroma and flavor soon after being ground, which is why so many people grind at home. Grinding right before use is the best way to ensure that none of the aroma and flavor is lost
