GRINDING YOUR COFFEE

Whatever your preferred brewing method—filter coffee or espresso—you will need to use ground coffee. Everyone knows that coffee powder is produced by grinding the roasted coffee beans in a coffee grinder. What people don’t tend to realize, though, is that different models of grinder give a finer or coarser grind, producing ground coffee exhibiting different qualities and suitable for different uses. So it is important to consider your choice of grinder carefully if you want to be sure of obtaining your perfect shot.

Why invest in a grinder?

Given that coffee merchants are able to produce different grinds for different brewing methods, there seems to be little need to own your own coffee grinder. But whether you are a newcomer to the world of coffee or a well-informed enthusiast, here are two good reasons to invest in one. The fact is, you cannot really be a true espresso connoisseur if you don’t own a coffee grinder. For a filter coffee drinker, it is less essential. Whatever the case, a coffee grinder will guarantee you an exceptional coffee!

GRIND SIZE: A MEASURE OF THE FINENESS OF THE GRIND

COFFEE THAT IS ALWAYS FRESH 1

Ground coffee does not keep well. The transformation of beans into powder produces two associated reactions: the release of CO₂, a natural preservative contained in the beans, and the acceleration of the oxidation of the aromatic essential oils in the coffee (known as caffeol or caffeone) and other flavor components when they come into contact with the ambient air. So once the packet is open, while coffee beans can keep for several days, for ground coffee the storage time is no more than a few hours.

CONTROLLING THE FINENESS OF THE GRIND 2

The fineness of the grind (or grind size) is a fundamental variable that can be adjusted according to the desired result and other parameters. The espresso extraction time and the coffee balance are affected by the temperature and humidity of the air. Hence the barista has to adjust the grind size several times a day. This is why it is not advisable to buy coffee that has already been ground to a certain fixed grind size.

The right grind for each brewing method

Different methods of brewing coffee require different grind sizes. Adjusting the grind size allows you to vary the speed of extraction of the coffee’s flavor molecules. The finer the grind, the greater the surface area in contact with the solvent—in this case, water—and the faster the coffee components dissolve: espresso needs fine-ground coffee to compensate for the fact that the brewing time is short (less than 30 seconds), whereas a French press, with its four-minute infusing time, requires a coarse grind, which helps keep bitterness to a minimum and limits the amount of sediment in the cup.

WHAT GRIND FOR WHAT METHOD?

WHY IS A SIZE RANGE STATED FOR EACH METHOD, RATHER THAN SIMPLY A SINGLE SPECIFIED SIZE?

Because there are other variables involved:

• the coffee bean itself (variety, density, roast level, etc.);

• the coffee dose required (the higher the dose weight, the coarser the grind required);

• the time elapsed since roasting (a fine grind can compensate for a lack of freshness);

• climate conditions (humid air calls for a coarser grind)…