A burr grinder, also known as a burr mill, is a type of coffee grinder that uses two revolving abrasive surfaces to grind coffee beans into a uniform size. The two surfaces are set at a distance usually set by the user, and the resulting ground material is coarser when the surfaces are far apart and finer when they are closer together. Burr grinders can be powered electrically or manually, and they are widely recognized for their consistency, quality, and overall uniformity.

Burr grinders are different from blade grinders, which use a propeller-like blade to chop up the beans. Blade grinders can produce unevenly sized coffee grounds, leading to inconsistent brew quality. Additionally, blade grinders can create heat from friction, which can give the coffee a burned taste. In contrast, burr grinders produce particles of a uniform size determined by the separation between the grinding surfaces. They also produce less heat from friction compared to blade grinders, which is better for keeping the flavor and aroma of the coffee beans intact.

There are two main types of burr grinders: conical burr grinders and flat burr grinders. Conical burr grinders use a cone-shaped center burr with an outer serrated burr that helps produce well-ground coffee time and time again. Flat burr grinders feature two donut-shaped burrs that face one another with very sharp edges. This design allows the beans to stay between the burrs until they are perfectly ground up, as opposed to conical burrs which can allow the beans to shoot out and stay somewhat intact.

Overall, burr grinders are a great option for those who want to grind their coffee beans at home and achieve a consistent grind size.