Coffee Machines

Coffee basics: why the grind of your coffee is so important

The ancient practice of alchemy was a blend of the beginnings of philosophy, magic and chemistry. Alchemists searched for a mysterious substance called the Philosopher’s Stone, that would transform base metals into gold. They also believed in the elixir of life – a magical potion that would bring health, wealth and immortality. At De’Longhi, there’s a magical potion we’re obsessed with. It’s called coffee, and there’s certainly an art and a science to making it well. 

Why you should care about the grind of your beans

Nothing is more appealing than the aroma of freshly ground coffee beans. The rich, complex scent and correspondingly delicious taste are what make a perfectly brewed coffee, well – perfect! Getting that aroma and flavour from bean to cup is the obsession of the best baristas, and they know that the density of the grind can make or break a coffee.

Here are some tips to help you achieve the perfect grind.

The daily coffee grind

First things first; you must grind your beans fresh each time you make a coffee. Why? Because grinding your beans increases their surface area which means that volatile organic compounds (VOCs) are released quicker, either into the water or the air.

Put simply, if you let your ground beans sit around for more than 45 seconds, much of their beautiful aroma and rich complex flavour disperses into the atmosphere and not into your coffee. This can make for a dull, flat-tasting coffee.

Match your grind to your brewing method

There’s a balance to be struck between the density of your ground beans and the method you’re using to brew your coffee. When your beans are finely ground, you increase their surface area, so the hot water has more coffee to act on, releasing more flavour. This means that coarsely ground beans need to be exposed to hot water for longer than finely ground beans.

Different methods of brewing expose the beans to the hot water for different lengths of time, and at different pressures and speeds. Bringing the coffee particles out of the beans in this way is called ‘extraction’ and it’s a fine art. If your coffee is under-extracted, the crema will be thin with large bubbles and the body light and watery and the taste will be weak. If your coffee is over-extracted, the crema will be a thin dark foam and the body will be weak, with the taste being strong and astringent. An espresso grind, for example, should be fine to very fine; while a stovetop espresso maker needs a slightly coarser grind.

What does this mean for the home coffee maker? Whichever method you’re using, if your coffee is a little weak, try a finer grind next time. If your coffee is too strong or bitter, try a slightly coarser grind.

Match your grind to your bean

All coffees beans behave differently in the grinder. For example, darker roasts are brittle and should therefore be ground more coarsely, while a lighter roast can be ground finely. The origin of your coffee also has a bearing – coffees from higher altitudes need to be ground more finely than those from lower altitudes. Very high altitude beans include those from Ethiopia, Colombia, Kenya and Guatemala. Medium to low altitude beans come from Brazil and Hawaii.

Remember, when you try out a new type of coffee bean you may need to change the density of your grind.

Choose a good coffee bean grinder

There are two main types of grinders available – the burr grinder and the blade grinder. A burr grinder results in a much more even grind, which is a good thing. When the beans are smashed in a blade grinder, the resulting grind consists of bigger pieces and very finely ground pieces, which leads to a coffee that’s both over-extracted and under-extracted.

A difference of mere hundreds of a millimetre in the grind can make a difference to the taste of the coffee. This makes it especially important to have a good burr grinder espresso – one that can grind the beans to a very fine (but not too fine) density.

Luckily, each De’Longhi bean to cup coffee machine has a burr grinder as standard. We don’t like to compromise.

We hope these tips help you to experiment with your grind and brewing method until you find the magical combination that’s perfect for your tastes.