To make the brewing procedure easier, whole coffee beans are milled, or ground.
Brewing is significantly impacted by the grind’s fineness. A coarser grind is needed for slower brewing techniques than for quicker ones since the coffee grounds are exposed to warm water for a longer period of time. When beans are ground too finely for the brewing process they are employed in, too much of their surface area is exposed to the heated water, which results in a bitter, harsh, “over-extracted” flavour. On the other hand, a grind that is too fine will result in weak coffee unless more is utilised. A uniform grind is greatly desired since the fineness of a grind is very important.
Finely ground coffee can be brewed quickly if a method is utilised where the length of time the ground coffee is exposed to the heated water is programmable. While using less ground coffee, this creates coffee with an identical flavour. If a blade grinder is not being used to grind very large quantities of coffee, such as in a commercial setting, then frictional heat does not build up in the ground coffee. The most effective extraction is possible with a fine grind, but coffee that is ground too finely can take longer to filter or screen.
Due to the larger surface area exposed to oxygen, ground coffee deteriorates more quickly than roasted beans. Many people who consume coffee ground their own beans right before brewing.
Reused coffee grounds can be used in the garden, on the skin, or for hair treatment. These can be used to make biodiesel as well.
Burr grinding, chopping, hammering, and roller grinding are the four ways to prepare coffee for brewing.