Now, the next step in the process of brewing a great cup of coffee is to pick which brewing system you are going to use. This choice is based on a couple factors: the coffee that you are brewing, the size of cup that you want to brew and the amount of control you want to have over the brewing process. As the current field of brewing options is extensive and ever expanding, we want to dial in to a select few methods which form the foundation of coffee brewing. Fortunately, this range can be broken down into two major categories: surface contact extraction and pressure assisted extraction.
Surface Contact Extraction
This is the title I like to give to any brewing method which relies solely on water contact with coffee grounds to promote extraction. We can further break this group up into filtered and unfiltered systems. While there is nothing technically fancy about this method, the variation in apparatuses is incredible. From the retro styled and filtration dependent Chemex to the classic French press, surface contact extraction runs the gambit of form and function.
The French Press
The obvious main player on the unfiltered team. Oftentimes a burgeoning coffee brewers first tool on the path to better coffee, it offers ease of use and a relatively low margin of error. Coarse ground coffee is dumped into a brewing chamber, hot water is poured on top, the lid is replaced and contents are left to steep for 4 or so minutes. While convenient and straightforward, this technique has a few (admittedly personal) detractions. First, and possibly at the top of a new brewer’s list, it’s messy. The grounds need to be disposed of, but after pouring out all the brewed coffee, you are left with a moist clump at the bottom of the chamber that oftentimes will need to be scooped out. (It should be said that it is never a good idea to wash coffee grounds down the sink as they do not decompose as readily as other organic materials.) Secondly, and more important to the experienced brewer, the lack of paper filtration leaves you with a very heavy and bold brew. This serves some coffees such as city roasted Latin American beans well but should rarely be applied to more nuanced or light beans. Be especially wary of light roasted coffee as it has the tendency to come out completely vegetal and under extracted.
Overall, the French press provides an excellent upgrade from a standard button-press drip brewer but should not be the only tool in a brewer’s arsenal if they want to optimize their coffee experience.
Full Immersion (Cold Brew Methods)
Less popular during the winter months but steadily increasing in overall use are the methods of cold brew extraction. The basic idea is to take the French press system but increase capacity to brew large quantities of concentrated coffee. This is achieved by full immersion in cool water for up to a few days. This has two interesting consequences: cool water has less energy than boiled and therefore extracts different volatile compounds, and the ratio of coffee to water is tailored to produce a heavily concentrated coffee that is meant to be diluted before consumption. While not a logical choice for the novice brewer, if you find yourself drinking a great deal of cold brew, it may behoove you invest in a cold brew system to really nail that flavor profile you enjoy. Its also incredibly cost effective as the concentrate can be stretched with water and stored in the fridge for weeks.
The workhorse of the filtered group and often the featured method of coffee shops that offer pour overs. Developed by the Hario company, originally a Japanese chemical glass company, it gets its name from the fact that the brewing chamber is composed of a cone whose walls meet at 60 degrees. This has a couple implications in the brewing process that are beyond the scope of this article, suffice it to say that number was not picked at random. The V60 also features a rather large drip hole at the bottom and ribs that run the contour of the cone. These work in tandem to direct water flow and allow for even contact of extraction through the brewing process.
It can be quite daunting to use a V60 at first as the large hole can lead to quick brew times and under extraction, but there is a reason this system is still sworn by so many barista champions. As variable as the brew process can be, it means the V60 can brew just about any type of coffee. From natural Ethiopian coffees to washed Colombians, the V60 is really the brew all system when it comes to pour overs. The only type of coffee I would suggest one stray away from is darker roasted coffee as there is a point where the roast becomes the dominating flavor, and it is not really worth the hassle of the V60 to highlight this single dimension.
Yet another method developed as an offshoot of chemistry, the Chemex system was invented in 1942 by Peter Schlumbohm, it employs a paper filter that is around 25% thicker than those employed by the V60 and other similar systems. This results in a longer extraction period as greater clarity and crispness in the cup. The thicker paper works to filter out more volatile oils and compounds from the coffee, which tends to highlight lighter and brighter notes. Perfect for those naturals previously mentioned, as well as more delicate Costa Rican or Mexican beans. Once again, darker roasted coffees are not suited for the Chemex as it will be stripped of internal oils that rise to the surface through roasting. This results in a rather shallow cup with no bodies and an overall muted flavor.
Pressure Assisted Extraction
Likely the most familiar system that employs pressure in the extraction process. Espresso consists of a layer of emulsified fats and compounds atop a small quantity of very concentrated coffee. As previously discussed in our article on grind (link here), espresso machines employ a very fine grind to maximize surface area during the short brew time (40 seconds or less). As espresso machines are expensive, and the brewing process itself very temperamental, this is really only a system for diehard brewers and aficionados.
Resting somewhere between pour over and espresso is the AeroPress, although I would still consider this under the pressure assisted umbrella. Grounds are loaded into the brewing chamber and set to steep for a short period (20-50 seconds) before being plunged through a mesh filter and directly into the cup. The fine grain of the mesh filter along with the finer grind result in a brew that is an amalgamation of espresso and pour overs. You can use a paper filter to clean up the profile, but plunging without one will result in the brew oils being injected right into the cup, much like in a French press. Look for a heavy body and depth of flavor without the paper filter, and a cleaned up, more rounded profile with.
As previously stated, this is only a cursory glance at the many methods one can employ to brew coffee. Among the unlisted are the Kalita Wave, Stagg, Phoenix 70, Vacuum pot, SteamPunk and many many more. If it seems like all too much, I suggest talking with your local coffee shop employees about their favorite brew methods. In reality, any handmade method is going to produce a better cup than a Keurig (always) or auto drip systems (usually). If you are serious about your coffee quality and are looking to improve your home brewing, pick a single system and become as familiar and comfortable with it as possible. Make it your own. Experiment. But most of all, enjoy the coffee you produce.
Hill Tree Roastery Coffee Education Advisor