Whether you're just getting into home brewing or have a set up that would make James Hoffmann raise an eyebrow, it is crucial to understand the basics of grind settings. For the sake of ease and approachability, let's break the grind settings into three main categories: 1. Fine Grind, 2. Medium Grind and 3. Coarse Grind. Using these three distinct categories you will be able to understand the basics of why grind setting is so pivotal to a good cup and which settings are best suited for which brewing methods.
Fine Grind
If you are the owner of a home espresso machine we're looking at you. Espresso takes two key factors into consideration in tandem with its fine grind size: 1. high pressure and 2. short extraction times.
When you go to grab your favorite latte from your usual spot there is a reason the drink takes much less time than a manual pour over. And that is because the espresso machine is using high pressure (the standard is 9 bars) to push water through very fine grounds in a short amount of time (typically around 30 seconds) to produce a balanced double shot. For a quick visual, think of sand and how much time it takes water to move through it. Espresso is the same way, in that it is the least permeable of any brewing method, which is why we need machine operated pressure to expedite the process of extraction.
Point of Reference: On our in store EK-43 grinder, with a dial ranging from 1-11, 1 being the finest and 11 being the coarsest, we grind espresso on a 2.
Medium Grind
The setting with the widest range and covering the largest amount of brew methods, medium ground coffee has a lighter, flakier hand feel. Again, for visual purposes, imagine water being pushed through or trickling through sand. Now imagine how much more quickly water would move through say a stack of pebbles. That is, in essence, the jump from fine to medium grind. As we make the grind more coarse, the extraction process takes less time as a direct result of water having to go through less mass. Everything from Aeropress, V60, Kalita, Chemex will all be found on this spectrum of medium grind, with Aeropress being more medium/fine and Chemex being more medium/coarse.
Point of Reference: On our in store EK-43 grinder, with a dial ranging from 1-11, 1 being the finest and 11 being the coarsest, we grind Aeropress at a 6 and our drip coffee at a 9.5.
Coarse Grind
Last but certainly not least, we have our coarse grind. If you are a fan of cold brew, you are also a fan of a coarser grind. The largest of all the grind settings, this is the method best suited to a brewing process that involves steeping. Cold brew, unlike other forms of iced coffee, avoids using heat in the extraction process by using room temperature water and 18-24 hours of extraction time. This results in a less acidic, smoother taste.
On a much smaller scale, but similar principle, a French Press does use heat (hot water) but this coarser grind setting to produce maximum extraction in a roughly four minute time frame. With the coarsest grind setting water has the most amount of surface area to 'play with' during the extraction process. Instead of picturing water moving through sand as we did with the fine grind, or pebbles with the medium grind, think of water passing through full sized rocks. This is analogous to the coarsest grind settings.
Point of Reference: On our in store EK-43 grinder, with a dial ranging from 1-11, 1 being the finest and 11 being the coarsest, we grind for french press and cold brew at an 11.
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