Space nerds love caffeine. The original source of this wondrous drug is coffee – or more specifically, the two varieties of the plant which are widely cultivated. Not everyone drinks coffee, but those that do often find it hard to do without, and any long-term coffee drinker has probably had the experience of drinking something that tasted like battery acid and burnt hair to get their fix. The real tragedy of such traumatic beverages is that producing awful coffee is entirely avoidable; this article provides a handy practical guide on exactly how to steer clear of sub-optimal brewing.
To be clear right at the start, this article is not going to explain how to make the best cup of coffee ever. That is a matter of personal taste. It will tell you how to get the most out of whatever you are brewing, regardless of whether it is the budget conscious store-brand grounds or premium whole bean. Additionally, the information presented here is not all-inclusive, and should not be taken as the final word on coffee brewing. Rather, it is a list of practical tips for the layman, which the author picked up while working several years at a coffee roaster and distributor.
So, the first step in getting the most out of your coffee actually takes place before you buy your coffee. It involves understanding what exactly you are buying. As mentioned above, there are two different types of coffee in wide cultivation. Coffea arabica is the most widely grown coffee species, accounting for between 75 and 80 percent of coffee grown worldwide. Arabica coffee has a relatively mild flavor that accounts for its popularity, but it is fairly picky about where it will grow well. The second species is Coffea robusta, so named because it is much hardier than Arabica, growing in land where Arabica will not, while producing higher yields.
On the other hand, it produces beans with a much bitterer flavor. It is typically found as filler in cheaper blends due to its lower price, though it is also used in espresso and Italian coffees for its flavor and higher fat content. The upshot of all this is that when buying coffees at the lower end of the price range, a buyer looking for a mildly bitter cup should note if the can is marked 100% Arabica; if it is not, it will likely contain some percentage of Robusta beans with a correspondingly stronger bitter flavor.
The second thing to be aware of is where the coffee was grown. Different climates, soil compositions, altitudes, amounts of shade, and the harvesting method used all impact the flavor of the finished product. A coffee drinker can experiment with brands and different regions to find what they prefer. For example, 100% Columbian coffees are far from identical, though they all come from the same country. The roast matters as well. Roasting coffee beans breaks down some of the bitter compounds in the beans while developing the fats, oils, and sugars to give the coffee its flavor. How far this process goes has a huge impact; identical beans roasted to different temperatures will have very different flavors.
At this point, a brief explanation is required about just what brewed coffee really is. Coffee has hundreds of biologically active chemicals, with caffeine being merely the most prominent. For a more detailed explanation of the different compounds and their effects, this article by the Royal Society of Chemistry makes for an interesting read. Without delving too deeply into the science, coffee is basically caffeine, sugars, fats, oils, bittering agents (bitter tasting chemicals), and sediment washed out of the grounds by hot water. The temperature of the roast, brewing method, treatment of the grounds prior to brewing, and storage of the coffee after it brews all impact the flavor of the final product. If the drinker desires a mild cup, which is to say a less bitter taste, the goal is to extract and then preserve as much of the fat, sugar, and oil as possible while minimizing the bittering agent extraction – this is where the not ruining coffee part really starts.
The first step to getting the most out of the cup is to prevent the coffee grounds from going stale before brewing. Stale grounds will typically brew a cup with an odd sour flavor. Coffee oxidizes when exposed to air, much in the same way that a cut apple goes brown. Because ground coffee has so much surface area, the oxidation can destroy significant amounts of the desired flavoring agents if allowed to go far enough. To prevent coffee grounds from going stale, expose them to air for no longer than 15 minutes before brewing. Ideally, each “brew” of coffee would come in an individual package. If coffee is in an open can, keep the lid on as much as possible and avoid stirring; the top later will provide some protection for the grounds under it.
Whole bean coffee is far less vulnerable to oxidation, and will keep much longer. Whole beans are typically packed in bags with a one-way valve. This helps to ensure freshness, as coffee emits significant quantities of gas for the first twenty four hours after roasting (enough to pop bags like balloons if they are sealed too quickly) and it will displace nearly all the oxygen in the bag. The valve prevents fresh air from getting in, keeping the beans fresh for months on the shelf. Once a bag is opened, it should last at least two weeks if closed after each use. When grinding whole bean coffees, simply follow the fifteen minute rule above, and be aware that the finer the grind the faster it will stale out.
Next is choosing the right equipment to brew your coffee. There are two ways to ruin good coffee during brewing: over extraction and burning. Over extraction is a result of running too much water over the grounds; caffeine, sugars, oils, and fats are all more soluble in water than the bittering agents and will be extracted first. After those are rinsed out, running more water over the grounds just makes the cup more and more bitter. This property of extraction also allows for the ultimate brewing dick move, where the brewer drinks the first cup out of the filter instead of letting it mix with the rest of the pot, guzzling its delicious smoothness and leaving everyone else with bitter brown funk-water. Burning coffee is exactly what it sounds like, exposing the brewed liquid to enough heat to destroy the flavoring agents. Anything hot enough to boil the coffee will burn it with prolonged exposure.
This means that two brewing methods need to be avoided at all cost. These are simply boiling the grounds on a stove, or using a coffee percolator, which both boils and over extracts as part of its operation.
The most commonly used method in use is drip brewing. This makes a pleasant, clear cup, and if done properly it will yield an excellent product. However, there are two things that a user can do with drip coffee that will cause problems. The first is to use two coffee filters, or putting a filter in a machine with a screen already built into it. A drip brewer stews coffee grounds in near boiling water for a specific amount of time. Reducing the outflow rate of the brewed coffee keeps more water around the grounds longer than intended, which results in over extraction. The second problem is that many drip brewers use a glass pot on a burner to keep the coffee hot after it brews. Typically within a half hour of brewing, any coffee left on a burner will be scorched beyond recognition. A better option is a vacuum flask, which will keep coffee piping hot for hours.
Another option is a French press, coffee press, or plunger: essentially a screen that forces grounds through a cylinder of hot water. This will produce a much more textured and stronger tasting cup than drip coffee, since it allows much more sediment into the cup. For coffee drinkers looking to make their coffee stronger without over-extracting, these are a great option, though they may not produce as much coffee for the grounds as a drip brewer. Single-cup brewers like the Keurig can also produce reliably good coffee, though they are relatively expensive.
At the end of the day, or more often at the beginning, doing the right things to get the most from your coffee is not hard to do. Once the process of brewing has been mastered, a drinker who wants to become a coffee connoisseur need only try different beans, blends, and roasts to figure out what they prefer. While there is no right answer for what makes great coffee, avoiding the wrong ones will never hurt.
This article originally appeared on TheMittani.com, written by FearlessLittleToaster.