Here I share tips to help you master the grind.
Also see: How to make delicious coffee the basics In a previous blog I covered the basics to brewing delicious coffee.
One of the key points was the importance of the grind in controlling extraction, and the importance of good extraction for a balanced and tasty cup. Here I share tips to help you master the grind. Around 30% of the coffee bean is water soluble although it is has been analysed and is widely agreed with in the industry that only 18–22% is desirable in the cup. Leaving the other influences on extraction aside it is easy to appreciate that the longer the brewing water is in contact with the coffee the more solubles will be released whilst at the same time the finer the coffee is ground the greater the surface area and so the quicker the solubles will be released. This helps to explain the very important difference in grind between:
Fine grind – soft to touch with some grittiness
Brews in 20 – 30 seconds
Ground medium fine – table salt
Brews in 1-2 minutes
Filter / V60 / Moka Pot
Medium grind – caster sugar
Brews in 3-4 minutes
French Press (Cafetiere) / Clever Dripper
Coarse ground – granulated sugar
Brews in 4-5 minutes
Diagram of fast flow vs slow flow depending on the coarseness of the grind.
Pebbles – too coarse, under extracted Sand – too fine, over extracted
Flat burrs from an electric grinder
The burrs are held firmly in place facing each other within the grinder and rotate at speed to grind the coffee. The gap between the burrs, will be roughly the size the coffee is ground down to before it exits the grinder. For an even extraction we need a grind that is as uniform as possible with a minimal amount of ‘fines’ (dusty particles). Grinders with blades that chop up the coffee will not achieve a uniform grind in the same way. When we make changes to the grind we are moving the blades closer together (finer) or further apart (coarser) simple! It is usually indicated on electric grinders how to do this and on hand grinder it is a simple as tightening or loosening the nut that hold the blades together
Collar of an electric grinder with adjusments
Nut of a hand grinder