The recipe to achieve great coffee relies on the control of many elements. Next on the list we discuss the Grind size – thought to be one of the most challenging but vital elements to master extraction. Whether your method be espresso, plunger or one of the mode-du-jour soft brew approaches. Traditional thinking states wholeheartedly that when it comes to grind, fresh is best. There are new theories on the table however, that consistency of grind is just as important if not more so; and has some companies favouring machine ground coffee for home users vs. fresh hand-ground coffee. An uneven grind will produce an uneven extraction and a less than perfect final product. What can be agreed upon, is to effectively extract the flavours of the bean, the coffee must be ground to the right particle size. Espresso is ground fine; as this creates smaller coffee particles for a fast extraction time. Smaller particles shorten the distance from the center of each particle to increase the rate of the extraction of oils, soluble, and other flavoring materials. Soft brew methods require a courser grind, as the larger surface area is important to the longer and slower extraction time, drawing out the soluble compounds over a longer period of time.
There are several factors acting on the bean that affect the behavior of coffee grinding: Moisture content, degree of roast, and bean brittleness. Moisture content of the beans subject to water quenching such as Decaf (using Swiss Method) has a greater tendency to grind inconsistently. The degree of roast translates to a lighter roast being more pliable and consistent when ground, whereas a darker is more brittle due to a greater loss in moisture. Bean brittleness can also be affected by how the beans are processed; natural, or wet; and altitude; where as a tree perched on tall mountains tends to be denser than low altitude.
Finally, the type of grinder you use bears great impact on the consistency of the ground coffee produced. Grinders with electronic burrs vs. a blade grinder are the industry standard to achieve consistency no matter what grind and method you will use. Whilst the price tag may be harder to swallow than a hand-grinder, you really do get what you pay for. You’ll get better performance, longevity and overall more enjoyable experience on your coffee journey.