Coffee Grinding - Why It Is Important !
Everybody wants to drink and serve the best possible coffee. Grinding whole beans at home and a basic understanding of grinding coffee correctly can really help make the most of what you've got.
Coffee beans are ground to allow flavour to be extracted from the bean in water to provide a cup of coffee. The size and quality of grind has a significant and very easy to detect effect on how a coffee will taste. Selecting a grind can prove a challenging and frustrating task but grinding fresh and to the correct size really makes a huge difference. This is because as the coffee comes into contact with water, different flavour types come out at different times. First, you get acidic, sharp flavours, at the end you get increasing bitter flavours and hiding somewhere in the middle are the juicy sweet joyous flavours we all love.
The correct extraction of coffee is determined by how long the water is in contact with the coffee and how much of the coffee is actually in contact with the water. This is determined by the size of the ground coffee particles. A correctly extracted cup of coffee, where the coffee has met the water for the right amount of time, will taste sweet and delicious. Under extracted coffee will taste salty or sour and over extracted coffee will taste bitter or burnt. By tweaking grind size and tasting your coffee you should be able to ‘dial in’ your grinder and grind size to produce great coffee.
How we brew coffee and how long the water is in contact with the grinds will determine the specific size of grind you need. For an immersion brew such as a cafetiere where the coffee will sit in the water for 4 minutes, you need a very course grind to extract the flavour slowly. If you put in a very finely ground espresso coffee into a cafetiere, the small particles, with a high surface area, will over extract and however wonderful the coffee you have bought is, it will taste very bitter. Similarly an espresso machine, where water is in contact with the coffee for a very short time, approximately 30 seconds or less, you need a very finely ground coffee to obtain a rich sweet taste. With too course a grind, the water will rush through, under extracting the coffee and producing a drink which at best will taste of lemon juice but at worst will taste very sour and salty. Not nice at all.
So, as a rule of thumb, if you brew a coffee at home and its tasting slightly bitter, you may have the grind a bit too fine. For example on the scale of 1-10 fine-course settings, if you ground at a 5, next time you grind you'll need to grind at a 6 and see if this tastes better. Similarly, if your last cup of coffee was just a bit too sharp and acidic for your taste, try a slightly finer grind.
Buying whole beans and grinding them correctly just before you brew is the easiest way to improve your enjoyment of freshly brewed coffee and the smell of freshly ground coffee is truly one of life’s great pleasures. Hand grinders, such as the Hario square grinder we supply start at very modest prices and are perfect for all filter brew techniques. A good burr grinder should provide an equal distribution of particle sizing at your chosen grind size, avoid the ones that claim to provide different sized particles as with these types it is impossible to obtain an even sweet extraction.