Pardon the pun, but grind size is no small matter. Controlling this variable allows you to improve the taste of your coffee, ensure repeatability, experiment with recipes, and more.
Unfortunately, many a wonderful coffee has been let down by its grind profile. From the wrong size (often caused by a poor understanding of recipes) to inconsistent grinds, there are many factors that can go wrong. The result? Anything from sour or bitter brews to an inability to recreate that perfect cup.
I spoke to Mark Vecchiarelli, Founder of Kruve and the creator of the Kruve Sifter set, endorsed by three-time Japan Barista Champion Miki Suzuki, five-time Canada Barista Champion Ben Put, and more. The tool reduces clumps and ensures grind consistency – so who better than Mark to break down grind size for me?
Grind Size, Extraction, & Flavor
When making coffee, our biggest goal is to achieve a controlled extraction. The final coffee flavor will depend on how many compounds are extracted from those roasted beans into our brew – something that is a delicate balance of water:coffee ratio, brew time, water temperature, grind size, and more.
The whole purpose of grinding our coffee beans is to increase the surface area coming into contact with water. And the finer or coarser the grind, the more or less quickly water can pass through it – affecting brew time as well as extraction efficiency.
A coarser grind has looser particles which, in turn, will allow water to move between them more quickly. The combination of less surface area and a shorter brew time (unless it’s immersion brewing) means that less extraction will be taking place. On the other hand, a finer grind has particles that are packed closer together. This means water takes longer to pass through the grinds and that there’s more surface area – leading to greater extraction.
Is your coffee mouth-puckeringly sour? Your grind size is too coarse – go finer. And if it’s a bitter brew? You have the opposite issue; try grinding coarser.
But there are several factors that help determine the exact grind size that’s best. Let’s take a look at them.