Grinding Coffee Beans
The coffee filter is made with fine pores or large perforations, devices that determine the choice of coffee grind. Filters lined with paper or cloth, or made of fine mesh are designed to trap colloids (insoluble coffee solids), eliminate sediment in the cup, promote coffee with clarity, and produce a light-bodied brew. Metal strainers punctured with large perforations are made to filter coarse grinds. The large holes allow insoluble solids to pass through; this leaves a little sediment in the cup, which promotes heavy-bodied brew with a pronounced taste.
Coffee grinds are extra fine, fine, medium, and coarse.
Extra fine-grind "pulverized" coffee has a consistency similar to powder; it is too fine to filter and is used to boil unfiltered coffee in an open saucepan, such as a Turkish ibrik.
Fine-grind "drip" coffee has a consistency similar to table salt; it is used in drip coffee makers, vacuum coffee makers, and espresso machines.
Medium-grind "all-purpose" coffee is the consistency of sugar granules and is also used in drip coffee makers.
Coarse-grind "regular" coffee is the consistency of cornmeal. It is used with a plunger pot or percolator.