How do I know what grind I should use for brewing?
Have you ever made French press coffee and struggled to push down the plunger? Have you bought a pour-over brewing device only to find that when you taste the results, it’s missing that special flavor you get at your favorite coffee shop?
There are several topics to consider when brewing coffee. For today, let’s look at why grind size matters and discover the best coffee grind for your chosen brewing device.
One of the most common situations we find ourselves facing while brewing coffee at home is discovering that the best grind size can be drastically different for a variety of brewing methods. The best way to begin the conversation is to think about rocks. In your mind, take a bucket of gravel and a bucket of sand (each with drainage at the bottom) and pour an imaginary gallon of water into them. Which bucket will the water pass through more quickly? Water will pass easily though gravel because there is more space between each rock. But it will pass much slower through sand.
This same principle can be applied to coffee. The more finely the coffee is ground, the slower the water will pass through it. Now that we have the basics of water flow, we need to address the wide range of brewing methods and what grind size is best for each of them. Let’s concentrate on three drastically different grind sizes (coarse, medium, fine) and how they interact with coffee brewing methods.
Coarsely ground coffee — ground to a size similar to kosher salt — works well for brewing techniques that require a longer contact time with water and/or cooler water temperature. Cold-brew coffee that sits and suspends coffee grounds for a period of 18 to 24 hours in cold water works great for coarsely ground coffee, because it allows for (and requires) longer saturation of these larger coffee ground particles.
The other brewing method commonly used with coarsely ground coffee is the French press. The French press typically allows for full saturation and immersion of coffee grounds suspended in nearly boiling water for about 3 to 4 minutes. This situation allows for proper extraction of the soluble materials in the coffee particles.
The sweet spot between coarsely ground coffee and finely ground coffee is the commonly used medium grind, which is similar in size to coarse sand or table salt. You can apply this grind to most of your cupping adventures, along with pour-overs and even your basic coffee maker. Really it works well with anything that typically calls for #2 or #4 paper cone filters.
To get really technical, there’s a scientific measurement for the perfect “medium grind” using microns. Medium ground coffee is typically around 841 microns or screen #20 as according to the SCA cupping protocol. But the more descriptive approach is “it’s like comparing Nebraska lake sand to California beach sand.”
Finely ground coffee has the look and feel of fine beach sand or slightly finer than standard table salt. Again, a wide range of brewing techniques use finely ground coffee, and these are traditionally found using a moka pot (stovetop espresso) or traditional espresso. These preparations are different but, both result in a much thicker beverage. The basic concept behind finely ground coffee is that it should be brewed within a shorter period of time in order to avoid over extraction.
Espresso preparation best explains the concept behind finely ground coffee. The finer the grounds the slower the water will pass through, but with espresso preparation, pressurized water delivery is introduced to help force water through the bed of coffee. Most pour over coffee brewing methods simply use gravity to do all the work, but pressure is required with espresso preparation in order to extract the necessary oils and flavors to deliver what is traditionally defined as espresso. There are a few modifications to these concepts (Aeropress), but overall pressure does matter, and it definitely plays a role in how best to choose your grind.
Here is a quick guide so you can match up the perfect grind size with your favorite brew method.
|GRIND SIZE||GRIND DESCRIPTION||BREWING METHOD|
|Extra coarse||Freshly ground peppercorn||Cold Brew|
|Coarse||Sea salt||French Press|
|Medium-coarse||Nebraska lake sand||Chemex or Clever|
|Medium||California beach sand||Pour-over or Auto Drip|
|Medium-fine||Table salt, fine||Aeropress|
|Fine||Finer than table salt, almost able to pinch and shape||Espresso, Moka Pot, Aeropress|
|Extra Fine||Pulverized powder or flour||Turkish|
To review, coarser ground coffee will typically use methods that require more contact time with water, resulting in a slower brew method. Finer ground coffee will result in faster brewing cycles and often requires the introduction of some pressurized force to help water pass through fast enough to avoid over-extracting coffee solubles that can lead to more bitter and astringent flavors.
To learn more about Arbor Day Coffee visit: arborday.org/coffee