In many parts of life, size is far less critical than purpose. In coffee, however, the size of your ground beans influences the time your coffee grounds are in contact with the water, how much of the delicious elixir is extracted from those beans and how fast water flows through the ground beans. Thus, the size of your grinds can significantly alter your final product.
As for the size you’re supposed to use? That depends on what you are trying to brew. The answer can vary wildly from very fine to extra course depending on your brewer and method.
Ground Size and Use
Here we have compiled a list of the most common and popular brewing methods and the ground size they need for optimum levels of flavor. Enjoy!
Turkish Coffee is an age-old classic as far as coffee goes, and was originally a delicacy reserved for the king, or as he would be called in Turkey, the sultan. As such, it requires an ultra-delicate and super fine grind. For this coffee, you are looking for coffee grounds that are comparable to powdered sugar. That is amazingly fine to have achieved in the 16th century!
Similar to the French press, the AeroPress is a manual brewer that is typically used for single servings. The recommended ground size for the AeroPress is something between medium and fine depending on your tastes. A finer grind will retain the water longer and thus have a stronger flavor.
Siphon brewers, work by using pressure to force water into the same chamber as the coffee grounds, then removing the heat to cause a vacuum, pulling the water through into the pot. This method also requires a medium to fine grind for the optimum levels of water to coffee exposure.
While most pour-over methods require a grind between medium and fine, it is essential to be familiar with your machine in particular because some of the different sized machines need different ground sizes as well.
Brewed under at least nine bars of pressure espressos require a very finely ground bean for the best flavor, though not quite as fine as the Turkish coffee’s grind. The optimum grind for espresso is more comparable to table salt than powdered sugar.
Using about 1.5 bars of pressure the Moka Pot forces steam up through the basket of grounds to steam coffee grounds. The coffee-infused water then falls back down to the pot after condensation. For optimal exposure time, a medium ground is recommended for your beans.
Typically requiring medium-course to medium ground beans, drip coffee is the most common brewing style found in homes, offices, and shops. The exposure time is managed by the very small hole in the bottom of the basket coupled with the flow onto the grounds that brings in around twice as much as what can run out at any given time. One reason this method is so popular is because of the ease of use and automation included in machines from a very low price point.
The French press uses immersion brewing, much like hot tea, where the coffee grounds are added to hot water and steeped for a while before being strained out. Due to the straining process, a coarse grind is crucial for a good cup from a French press. Using anything smaller is possible, but will lead to a cloudy cup of coffee. Or, sometimes even grit from the grounds finds its way into the bottom of your mug.
When using a cold brew, the coffee is placed in water that is at or below room temperature for one to three days, depending on the desired strength, before being strained. While any size of grind can be used for this, an extra coarse grind is recommended to avoid cloudiness, caused by tiny bits of suspended grounds, in the final product.
Single-cup coffee makers, such as Keurig, usually have the option of buying pre-ground and pre-portioned cups, but if you would prefer to make your own or use a machine that is compatible with just grounds, a medium grind is recommended. This size ensures that while you have an excellent exposure time, the grinds are too large to work through the machinery and make for a cloudy cup.
Figuring out grind sizes can be hard at first, but after some time, they start to make sense. For example, with Turkish coffee, no filter is used at all, so you will want coffee small enough to remain suspended in the water, so you don’t experience the sensation of having grounds in your cup while enjoying this old-world classic. Meanwhile, with a cold brew, you will want grounds as large as possible, because your end goal is a crisp, clear cup.