Burr Coffee Grinders
Grinding your coffee right before you make it is one of the most important factors in making great coffee, right next to buying fresh roasted coffee. There are two basic types of grinders. Blade grinders have a fast spinning blade that chops the coffee beans. The centrifugal force of this design can create very inconsistent particle sizes, with both finely ground powder and coarsely chopped pebble sized grinds. Coffee that is ground too fine will overextract, tasting bitter, and coffee that is ground too coarsely will not impart the full flavor of the coffee bean.
The other type of coffee grinder is designed to create a very consistent grind size. Burr grinders crush the coffee beans between a rotating burr and a stationary surface. This gives you grounds that are uniform in size and shape, from which the sweet, smooth flavors of the bean can be extracted reliably.