The Coffee Machine

Once coffee beans have been roasted, they must be ground down into smaller pieces to increase the surface area which is necessary for extraction. A fine grind size will give a faster rate of extraction, and vice versa. The right size coffee grounds must be used depending on the brewing method or equipment you are using. It’s always better to grind your coffee beans just before brewing, as stored coffee grounds become stale quickly.

There are basically two types of grinders – burr and blade. So, what’s the difference?

A blade grinder is the cheapest and most straightforward coffee grinder – the usual kind you will find in department stores. All you need to do is throw in the coffee beans, pop the lid on and press the power button – the motor and a blade does the rest. The grinding blade rotates, slicing through the beans and breaking them into small pieces. You can achieve a finer grind by leaving the grinder on a few extra seconds.

The downfall with this type of grinder is the lack of consistency of the grind size. Even when ground down to a finer size, the grounds will contain pieces ranging from chunks to powder. The problem with this is the finer ‘powdery’ pieces can burn easily in your espresso machine, resulting in bitter-tasting coffee.

The other type of grinder is a burr coffee grinder, of which there are two types – conical and flat blade. A conical grinder has two cone-shaped burrs opposite each other – the distance is adjustable to determine the size of the grind. Coffee beans are then fed between the blades and crushed into same-sized particles – one of the burrs remains stationery while the other rotates.

A flat blade grinder also has two flat and parallel blade burrs – these provide a shearing effect on the beans, resulting in a more uniform and larger surface area for extraction.

For more consistent-tasting quality a burr coffee grinder is recommended. There are several types of burr grinders available, the differences being speed, dosing and type of grind adjustment. Check out the Krups burr coffee grinder or the Nemox Lux conical burr coffee grinder for more information.

In terms of speed, there are three types; direct drive high speed, gear reduction low speed and direct drive low speed. The entry-level model of burr grinder is the high speed direct drive, where the motor is connected directly to the burrs. Unfortunately, heat affects the end quality of the grounds, the noise is unpleasant, and static causes the coffee to lump together. Even though there are disadvantages to this type of grinder, it’s still a great choice for producing quality grinds for a low price.

Gear reduction low speed and direct drive low speed grinders are most commonly found in cafes, and perhaps at the home of a dedicated coffee enthusiast. You’ll get hardly any static or heat and there is no noise – all of these factors due to a low RPM. The way it works is the low speed grinder has a high speed motor connect to the burrs via a set of gears. This reduces the speed but maintain the grinding power.

In terms of dosage, burr grinders are available in doser and doserless models. A doser is designed to handle a large volume of coffee, such as in a commercial setup. It allows you to grind the beans in batches into a doser container that usually holds up to six dosages. At home, you would normally only make one or two cups at a time, so you probably won’t need a doser, as you’re likely to end up with wasted or stale grounds, and extra cleanup.

In terms of grind size adjustment, there are stepped and stepless adjustment grinders. A stepless grinder allows you to have an infinite number of settings for grind size, where a stepped grinder has preset stops where the grind setting will stop at. If you’re very particular about your grind size, then you’ll probably want a stepless grinder so you can adjust it down to the last increment. Some of the stepped grinders will have more than 50 steps, which is usually more than enough to satisfy the pickiest of coffee connoisseurs.

If your budget permits, go for a direct drive low speed burr coffee grinder that is doserless. A good grinder is the most important tool when it comes to consistency and quality for every cup of coffee that you brew.