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When coffee beans have been roasted, the next step towards making them drinkable is to grind them down to a fine powder ( read more about coffee grinder here. The fineness of the grounds will have a huge impact on flavor, with a finer grind creating a far richer flavor. Of course, if the grounds are too fine, they’ll simply work their way through a filter and spoil the cup of coffee, so there is a point where you have to sacrifice flavor for smoothness in the final product.
But grinding coffee beans is, much like most parts of the coffee-making process, a nuanced art that can have a great impact on the flavor and smoothness of your caffeine fix.
Coffee grinding is performed by either a burr-based coffee grinder or a blade-based coffee grinder. The differences between the two are substantial:
BURR COFFEE GRINDERS:
A burr-based coffee grinder is a machine with two revolving ‘tearers’ that spins, rips and crushes the beans, without any risk of the beans becoming burnt. These type of coffee grinders are generally either wheel or conical in variety, with most connoisseurs preferring the quieter, aroma-preserving, and less-likely-to-clog conical grinders.
A conical burr coffee grinder can get your coffee beans down to a very fine and consistent powder without needing to go to high speed – they work at about 500rpm as opposed to the 10-20,000 rpm of a wheel grinder – which makes them ideal for the extra fine needs of Turkish Coffee ( How to Make Turkish Coffee ). The ability of conical coffee grinders to do their job without heating the grounds is what keeps the aroma intact, and the option of a variety of grind settings make the resulting product suitable for a wide array of coffee-making equipment, such as espresso, drip, percolators, and even French press.
The wheel-based coffee grinder, or disk-type, grinds at a faster speed than conical burr grinders, which warms up the grounds, but they do bring about a far more consistent grind, which is well-suited to most home espresso machines.
BLADE COFFEE GRINDERS (or CHOPPING GRINDERS):
Most commercially available grinders simply chop the beans into smaller and smaller pieces until you’re left with a powder, and sure, this will give you the coffee grinds needed to make a decent cup of coffee, but there’s also a downside to the chopping process.
The ground coffee from a blade coffee grinder has uneven particles which tend to be warmer, which does affect the aroma. These grinders also create coffee dust, which can clog up the works of espresso machines, or make it harder for filters to do their job. While chopping grinders are suitable for drip coffee makers, and can be very handy for chopping spices and herbs, they’re not the sort of equipment that a coffee connoisseur will have sitting on the kitchen counter.
There is another grinding option, which is known as POUNDING. This is usually the way grounds for Turkish coffee are created, and it involves pounding the coffee into a fine dust using a mortar and pestle. There’s simply no better way to get ultra-fine coffee grounds, but they’re far too fine to be used in any kind of coffee-making equipment.