If you think coffee flavor just comes down to the species of coffee plant and where it's grown, you've only touched the surface of what determines the flavor profile of your favorite coffee.
What Determines Coffee Flavor?
The following are the factors that go into making your favorite cup.
Terroir
The terroir refers to various environmental factors affecting the taste profile of coffee beans. Each coffee growing region around the world has unique climates, soil types, and altitudes. So, even before processing and roasting happens, the bean's green (unroasted) state is already influenced by its region. An estimated 70 countries produce coffee, with the largest producers being Brazil, Kenya, Ethiopia, Colombia, Vietnam, Peru, and Indonesia.
Variety
Typically, in specialty coffee, the species Arabica is what is roasted and served. This species can be broken down into hundreds of “varieties,” or branches off of the Arabica species. Each variety will have its own sweetness, acidity, body, and overall flavor profile. Some of the most popular varieties currently are bourbon (and varietals such as pink bourbon / red bourbon), landrace, heirloom, and gesha.
Processing Methods
The three main processing methods include wet-processed (washed), dry-processed (natural), and semi-washed / honey (no honey is used in this process - this refers to the sticky mucilage layer being left on the bean when drying instead of washed fully). Washed involves pulping cherries and washing the fruit off of the seed, often producing a complex yet mellow / delicate flavor profile. Natural processing involves drying out the cherry in the sun, which delivers fruity flavors. The semi-washed / honey processes are more or less a combination of methods that leaves part of the sticky mucilage layer at varying degrees of intact.
Roasting and Brewing Techniques
There are three main roast levels in reference to roasted coffee:light, medium, and dark roast. Light roasts are acidic and just in the stage of development that allows for complexity of flavor / sweetness whereas dark roasts are more robust with bold flavors, such as chocolate / dark chocolate, burnt caramel, toasted marshmallow, etc. Medium roasts tend to be right in between the two, featuring rich / round flavors and a round body, while still maintaining a bright acidity and decent complexity.
Storage
Coffee beans let out gasses sealed in by roasting every day, surrendering more and more of the flavor as days go by. It’s helpful to store beans in airtight containers (once they have hit their ideal amount of time off of roast, which is typically roaster-recommended) and in a cool, dark place to increase longevity.
The Coffee Flavor Wheel
There's a range of coffee flavors, each of which is categorized into a larger flavor group forming part of a coffee flavor wheel, a tool used by professionals to create standardized terms for distinct flavor characteristics.
Nutty/Cocoa
One of the most common coffee flavors is nutty. Produced by a medium roast coffee with mid-level acidity, nuttiness can range from macadamia, walnut to almond flavors, and many more. Cocoa can range from milk chocolate to high-percentage dark chocolate, or from sweet cocoa to baker’s chocolate. To start, select a bean with a nutty or chocolatey flavor to enhance the profile.
Sweet
Sweetness can talk about anything from a fruity sweetness to a candylike sweetness, and everything in between. When assessing sweetness, think about the difference between a grape and a meyer lemon, a dairy caramel and a peach ring. How does each sweetness differ from one another?
Floral
The floral category can range from chamomile or tealike flavors, to jasmine, hibiscus, rose, lavender, or peony flavors. These are typically lighter-roasted coffees that tend to also have more pronounced acidity and sweetness. You should also use slightly hotter water for lighter roasts depending on the process of the coffee - 205+ for lighter roasts that are washed process, and slightly cooler for natural / experimental processed coffees that are more soluble.
Fruity
When it comes to flavor profiles of coffee, fruitiness is one of the most popular flavor categories in the current specialty world. The method processing also influences the taste characteristics of the coffee beans. For fruity flavors, the natural process of the bean and the fruit pulp drying out in the sun offers an absorption of the fruit from the bean's cherry, adding in deeply fruited flavors. The roast level also dictates how many fruit flavors will be present in the final cup and what kind of fruit flavors - typically lighter roasts showcase more complexity in fruity flavors, whereas medium roasts showcase deeper fruited flavors (darker fruit, apple, cooked fruit).
Sour/Fermented
This flavor group can typically point to flavors that detract from the overall profile of the coffee, aka “detractors.” While ferment isn’t always a detractor (and at times can be a contributor to the overall flavor) - sour is most often a detractor from the overall flavor. Underdeveloped roast profiles as well as under extraction in the brew process can produce a sourness in the cup, and some green coffees are sour due to improper processing. Ferment most often occurs in naturally-produced or experimentally-produced coffees - sometimes existing within the balance of the overall profile (contributor), and sometimes throwing the profile off (detractor).
Green/Vegetal/Earthy/Herbal
This category varies wildly, including attributes often seen as contributors, detractors, and some attributes that are quite controversial. Characterized by anything from herb and earthy attributes to green flavors of garden peas or coffee pulp, this category is quite vast. The earthy category can also include anything from fresh soil to sweet earth, and can overlap with “herbal” in terms of flavors such as sweet tobacco (often found in medium / darker roasts, or in certain terroir) Under developed coffees (in terms of roast) can often produce these vegetal qualities - often producing detractor qualities such as garden peas, coffee pulp, grassiness, and the like.
Roasted
Roast can range from pipe tobacco to burnt / over roasted, and both can typically be seen in darker roasted coffees.
Spice
Spice profiles include attributes ranging from cinnamon to black pepper and clove flavors. Indonesia is typically known for producing more spicy coffee attributes due to their general terroir.
Finding Your Favorite
Finding your favorite coffee profile can take some time. Experiment with various roasts, regions and flavors. Consider how you brew and drink your coffee at home. If you like milk in your coffee, perhaps a medium or a dark roast profile is better for you! Keep tasting and trying — finding "the one" takes commitment!