Let’s talk a bit about coffee the plant. The coffee tree is very sensitive. It likes to grow in moderate temperatures, but cannot withstand a frost. The only regions that fit the bill (on this planet, at least) are mountain regions in tropical climates. Most of the drinkable coffee in the world is from the species coffea arabica. The rest comes from the less desirable species "Robusta", named for its ability to sustain some harsher conditions than arabica. Basically, robusta is easier to grow, but not as tasty. Robusta is typically used as "fillers" in very cheap preground coffee, and as a natural flavor in food products like candy and ice cream. There are many other species of coffea, but they are not commonly in use as a beverage or food product. Suffice it to say that, if you’re drinking coffee right now, its very likely to be arabica.

So if all of the coffee worth drinking is the same species, what makes one coffee different from another?

Where a coffee is grown matters. This is because different combinations of water, soil nutrients, sunlight, humidity, temperature, elevation, etc. can bring out different flavors of coffee. For this reason, you can find drastically different coffees from different countries, different regions, or even from farm to farm.

The farming and harvesting practices might make the largest difference in how a coffee turns out. Coffee trees require regular pruning and care to remain healthy and produce quality cherries. Then, those fruits must be hand picked at peak ripeness. This requires lots of hard work, and many farmers simply don’t put that level of care into their work (or don’t know to).

Finally, I know we already covered that, for the most part, the species doesn’t matter. However, within the Arabica species there has been a ton of work in the past few years in cultavating varietals — specific strains and subspecies. Examples of varietals include Caturra, Bourbon, Pacamara, and Gesha. These variations, whether intentionally breed or selected from nature, can have pretty significant impacts in the flavor profile.

Once coffee is picked, it must be processed. Coffee processing is the act of extracting the seeds, which we for some reason refer to as the "beans", from the coffee cherries before being roasted, ground, and brewed. There are two seeds per cherry, and the method by which they are extracted impacts flavor. There are 3 primary methods.

Wet processing (also known as washing) is a method that uses water to separate the fruit from the seeds. The separated seeds are then laid out to dry for several weeks before being packaged and shipped. Wet processed (or washed) coffees tend to have a very clean and pronounced flavors.

Natural processing (also known as dry processing, sun drying, or simply natty) is a process where the harvested cherries are laid out on large, usually wooden, beds in the sun and left to dry. Because the fruit is left on the seeds, it has a chance to impart extra flavors on the seeds. These can be very fruity flavors, as well as wild, sweet, or even fermented flavors. Natural processed coffees tend to have added complexity because of the drying, however if left out too long, could get overly funky.

In between Wet and Dry processing, you have hybrids such as honey processing and pulped. This means that some of the fruit and pulp is removed, but some is left on, and the partially separated seeds are left to ferment for varying amounts of time.

Once the seeds are processed, they are packaged into cloth or plastic bags, loaded into shipping containers, and shipped all over the world to roasters.

FINALLY!!! The coffee has now made it to your local coffee roastery. It’s the job of the roaster to discover and unlock the flavor potential of a particular coffee bean. Depending on the makeup of sugars, fibers, lipids, etc. in a particular coffee as well as personal taste the ideal roast for a particular coffee could be anywhere from fairly light (sometimes known as a city or cinnamon roast) to very dark (also called french, italian, vienna, or my preferred burnt).

No matter the roast profile, the most important key to great coffee is that your coffee is fresh roasted. From the moment the roasting process ends, coffee begins to off-gas. This means that the roasted beans are giving off carbon dioxide. While off-gasing, the CO₂ is protecting the beans from being exposed to oxygen — the coffee killer. Once the CO₂ has all gone, the coffee beings to oxidize, essentially losing all character and flavor. With whole beans in an air-tight bag or container, off-gasing can last for up to a month. In an open or permeable container, maybe a few days. Once ground, coffee will lose its mojo in a matter of hours.

Now, you might be thinking "What was the point of all that?". You don’t live near a coffee farm. You have no way of knowing whether your beans were grown, harvested, or processed with care. You also most likely don’t have direct access to your roastery. How can this information be used to buy better coffee?

While its impossible to know for sure, you can find indicators of good practices by looking for details about the coffee on the bag label. Producers and roasters who care about the quality of their products will typically go to extra lengths to tell you about them. The more detail, the better. However, I would recommend walking away from a coffee that doesn’t at a minimum give you a roast date and a country (or countries if its a blend) of origin.

So, to get back to the bullet points, a great coffee is one that:

Immersion brewing refers to brewing coffee by soaking the grounds in water for a period of time. After the right amount of time, the mixture is then forced through a filter of some kind, which allows the liquid to pass through, and holding the undissolved grounds behind. Immersion brewing is most commonly done through some type of coffee press, such as a French press, or the newer and very popular Aeropress.

Coffee brewed using immersion methods tend to have bigger body, heavier mouthfeel, and therefore is more popular for use with coffees that have chocolately, nutty, or savory flavors. However, Immersion brewers are typically pretty versatile and can make great coffees across the spectrum.

If you are looking to get started with coffee, I highly recommend the Aeropress as a good place to start for its forgiveness and simplicity.

Drip brewing is the process of making coffee by water passing through a bed of coffee grounds. The grounds typically sit in a filter placed bed of some kind with a small opening in the bottom. Water is poured over the bed of grounds, wetting the coffee, and the extracted coffee flows out of the hole(s) in the bottom of the brew bed.

This is the method used by most automatic home coffee makers.

The key to making great coffee with a drip method is ensuring that the grounds all get wet evenly and at the same time. This can be a challenge and unfortunately is done very poorly in most automatic machines.

Pourover brewing is a sub category of drip brewing, which typically implies a manual process of pouring water over a bed of coffee. There are MANY different pourover devices available, but the two most iconic are probably the Hario v60 and the Chemex.

Despite lots of confusion, no doubt due to marketing fluff and other misinformation on the internet, the term espresso refers to a method of brewing, not a particular type, category, or flavor profile of coffee bean. Espress brewing is the act of forcing water through a compacted bed of coffee (a puck) using pressurized air. Standard espresso machines target precisely 9 bars of pressure as the ideal amount for brewing coffee.