When uncovered to air, coffee beans will begin to oxidize very quickly. Coffee grounds sustains more because it has a larger surface than the beans and lack the beans’ protective skin. A home coffee grinder allow you to stop the level of exposure and make a fresh grind. And most significant, grinding can be done when you need it.
Everything has a price, though. Choosing a top grinder can make the messy and long process of grinding much more rewarding.
There are three main types – blade, crusher and burr. The crusher is the ancient way of using a pestle and mortar to mash the beans. This process is difficult and gives an uneven grind because it just crushes them – not highly recommended. Blade grinders chop. The blade whirls, slicing the beans into small grounds – still not the best because the grains are not the same size and not all the oils are released, varying the flavor and dissipating a lot of the flavor. However, burrs use motorized plates with teeth that are pyramid in shape, allowing for the perfect grind. Better burrs allow for varied grain dimensions because the speed can be adjusted accordingly.
The burr allows for the perfect brew. Speed control keeps the heating of the beans low.
Burrs have two categories
Professionals prefer the conical. Nevertheless, it is noisy. Good ones can go up to 500 rpm. Top quality ones go up to speeds of 10 thousand rpm, with their blades spinning at about twenty to thirty thousand rpm. This allows for fine grinds for Turkish coffee, for example. Some come with a dial for continuous speed adjustments. Others have buttons for some varied 40 different speed adjustments.
Beyond that you should look for ones that are solid in assembly, easy to clean and ideally less noisy. They should also include a brush for cleaning and easy to remove upper type burrs (blades). Beware of construction materials that cause static electricity. This can let the grounds stuck to the blades and the container.
Other very nice feature is a timer and an auto-switch-off. It also helps to be able watch the beans as the grinding takes place. Without this you cannot decide if the grind is ready. So, try to find one that doesn’t use glass or darkish plastic as this hinders your view. You should be able to judge the grind by its color, but if you cannot see them then this is a problem.