As with any grinder, Burr Coffee Grinder's operate so that fresh whole beans can conveniently be loaded into the hopper and fed through to the [burr] grinding mechanism. Once those beans are ground finely enough they can pass through to a removable receptacle or directly into an espresso portafilter. Grinders using burr technology are known to produce a more consistent and unvaried grind because the burr system necessitates that beans are uniformly sent through a small passageway, and crushed at even levels before they can fit through to the receptacle. These grinders also provide the ability to grind at adjustable levels, with uniformity–allowing flavors to be evenly extracted from each grain as the coffee is made. Particularly high quality burr grinders may also feature a slow speed motor to reduce any heat generated from the friction of grinding, ultimately preserving the intended flavors of the coffee blend.