To get the best out of your beans with different coffee brewing methods require different grind sizes. A coarser grind is typically recommended for French Press, a medium is generally suggested for most of the pour-overs, except for Chemex, perhaps, and for espresso or Turkish coffee, you will need to go fine or even extra-fine depending on the espresso machine you use. The good thing is that AeroPress (especially reverse method) is more tolerant and suits a bigger range of grind sizes.
When brewing coffee, it is essential to achieve a controlled extraction as the final result will depend on how many compounds and what is extracted from your beans. In the end, coffee taste is a delicate balance of coffee to water ratio, temperature and grind size. And, well, your mood too. But more about that later :-)
When we grind our coffee beans we control the surface area coming into contact with water and also the time it takes for the same amount of water to flow through, i.e. slower in the finer grind and quicker in more coarse.
As a general rule, if your cup is to sour for your taste, try to go a step of few finer. And if it is a bit on a bitter side, try grinding coarser. However, there are few other factors you might need to keep in mind:
- Roast level - darker roasts are more soluble, and so you might use a slightly coarser grind.
- Age - Hopefully, you use fresh beans only; otherwise, you might want want to tweak brewing just a bit as the coffee’s flavors fade over time. Try grinding finer or step up the dosage while grinding coarser to compensate.
Communicating grind setting to your friends and interpreting other people recipes is another challenge. We are sometimes instructed to grind to the size of “table salt,” “kosher sea salt,” or “fine sand”, or even better, size 4M on Baratza Vario ceramic but 2W for the one with a metal burr. It would be so much easier to have the same language, but for now, you might need to look up recipes base on your precise model or calibrate your grinder.
So, hope we were able to convince you that getting a good and precise grinder is extremely important and worth its cost.