What Influences the Taste of Coffee?
Once you have a baseline understanding of what taste is and how to begin tasting specialty coffee, you may wonder how coffee becomes so dynamic and what factors influence the taste of coffee. Are you curious why you taste a hint of citrus? You may have begun to identify full-bodied coffees and wonder what makes them so bold. Many factors impact the flavors in your cup— the four main influences on taste include environment, processing, roasting, and brewing.
A Seed-to-Cup Journey
The simplified coffee journey from seed to cup. Each element will have an impact on flavor.
The beverage we consume as coffee begins as an agricultural product grown worldwide and is first affected by the environmental conditions in which it was grown. Once harvested, those beans undergo unique processing methods that impact the final product. After processing, the green coffee beans (the agricultural product) undergo the roasting process. Different variables, such as temperature, airflow, batch size, and drum speed, decided on by a roaster can enhance or diminish inherent characteristics of green coffee. All of these decisions impact the flavor potential of your final product. Information on your coffee bag, such as country, altitude, variety, process, and producer, becomes crucial. This information can tell us a lot about the coffee and help us determine which brewing method will best enhance the coffee’s natural characteristics. Everything from your chosen brewing method to the grind size of your coffee will affect your perceived flavors, tasting notes, and flavor characteristics in the final brewing stage of the seed-to-cup journey.
This overview will cover how each stage can impact taste and help you, the home barista, decide what coffees to buy and how to brew them to get the most out of your cup.
How the Environment Affects the Taste of Coffee
Coffee Farm in Manizales, Colombia
Climate, Soil, & Elevation
Like any other agricultural product, coffee beans are highly impacted by the climate conditions and soil composition of where they are grown. Generally speaking, coffee trees require well-draining, porous soil (volcanic or clay loam), sloped land (~15% optimal), and protection from direct sunlight. Direct sunlight can cause stress on the plant and inhibit the proper development of the coffee cherry. The optimal climate is humid, with consistent rain and weather patterns. This tropical, temperate climate ranges from 60ºF to 80ºF. A climate that is too hot could mean the coffee plant suffers. If the coffee blossoms, cherries, or plants get too cold, they may freeze and be destroyed. These specific requirements mean that the number of locations worldwide where coffee can be grown is limited.
The elevation at which a coffee is grown, measured meters above sea level (MASL), plays an essential role in developing sugars, acids, and complex flavors that ultimately lead to a delicious cup of coffee. Generally speaking, coffees grown at lower elevations (and warmer climates) often have less acidity and complexity than coffees grown at higher elevations (cooler temperatures). Higher elevations have a wider diurnal variation, meaning warmer daytime temperatures and cooler nighttime temperatures. This dynamic thermal environment is believed to assist coffee cherries in producing more complex acids and sugars during the day, while at night, this development is slowed, and the cherry stores them away. More sugar developed during this ripening process will lead to a sweeter, cleaner, more dynamic flavor profile.
Tip: If you want less acidity, look for lower elevations (below 900 meters). If you enjoy acidity (the sparkling sensation on your tongue), look for higher-elevation coffees (above 1,000 meters).
Plant Variety or Cultivar
Ripe coffee cherries from the Catuai cultivar
Variety refers to the botanical subspecies of Coffea Arabica, the coffee plant. Variety is often used interchangeably with the word cultivar, which is short for cultivated variety. These subspecies are all arabica coffee but are genetically distinct, can have different complex tastes, and thrive in different environments.
To better understand, think of another fruit that is a bit more widely understood, like apples. We’re familiar with different varieties of apples, such as fuji, granny smith, gala, and Honeycrisp. We know that each apple type has its unique color, taste, and texture. The varying levels of acids and sugars help determine what each variety will taste like. Some apples are more tart, while others are sweeter, meaning you probably have a favorite type of apple to eat. Coffee is no different.
There are several thousand unique varieties grown throughout Ethiopia (where coffee originated), but only a few are generally grown throughout the rest of the world. Typica (tip-ick-uh) and Bourbon (bur-bone) are two of the most commonly cultivated varieties. Farmers choose to grow specific varieties that thrive in particular environments. They consider factors such as yield potential, bean size, quality potential, how tolerant it is to disease, and whether it’s susceptible to wind or drought. Some varieties are selectively grown to produce a high yield, helping a farmer earn more money, while others are grown due to distinct flavor traits that can help create a higher demand and price for the farmer, like the highly prized Gesha (gay-shuh) variety. Gesha is known for its tea-like qualities, soft citrus acidity, intense floral aromatics, and delicate body. The Bourbon variety is known for its sweetness, while the Caturra (cat-ur-uh) variety might have a brighter acidity and less sweetness, comparatively. It is important to remember that the same variety grown in different environments will taste differently.
Country & Region
Goshen Coffee Company named their single-origin coffee after the country and region it was sourced from.
It may seem obvious, but the origin of the coffee has a significant impact on the way your coffee will taste. Beyond similarities in the environment, each country and coffee-growing region has its own infrastructure for growing and selling coffee. It often has long-standing traditions for farming, harvesting, and processing techniques.
Coffee generally grows along the Coffee Belt between the Tropic of Cancer and the Tropic of Capricorn, where ideal climate conditions exist. This range looks like a belt spanning the figurative waistband of the globe and can generally be broken down into the following origin zones:
Coffees from the Americas
Central American coffees are known for their classic mild and bright flavor profiles. These coffees are grown relatively high in elevation and are primarily made up of Bourbon, Typica, and Caturra varieties. As the vast majority of these coffees are processed using the washed method (see processing), they are often distinguished by their bright acidity and round body. They are often considered balanced and clean. South American coffees have something for nearly everyone, as there are a range of flavor profiles from balanced, sweet, and crisp to earthy, rich, and hearty. These coffees have great structure and are solid foundations for several blends. If you are looking for a great ‘everyday drinker’ or the perfect coffee to pair with breakfast, look no further than South America.
Coffees from Africa
Coffees from Africa are generally known for their fruity flavors, like blackberry in Kenyan coffees, berry notes in naturally processed Ethiopian coffees, citrus and floral qualities in washed Ethiopians, and jammy qualities in coffees from Rwanda and Burundi. The complex and dynamic flavor profiles of these coffees are just one of the reasons they are so loved and desired in the specialty coffee world.
Coffees from Asia and the Pacific
This area is distinct from other coffee-producing regions as the coffee sits at lower altitudes due to the island's geography, and domestic cultivation of coffee is considered more of a cash crop grown in backyard gardens than large farms or estate operations. These coffees generally have a full-bodied mouthfeel with intense earthy, herbal, or savory qualities. Indonesia has a reputation for being one of the most intriguing and unique regions in the world, mainly due to the Giling Basah (Semi-washed) processing used by many of the local producers. This processing method gives Sumatran coffee its distinct earthy quality, low acidity, and heavy body.
How Processing Affects the Taste of Coffee
The pulp and seed of the coffee fruit
Like an apricot or a peach with a pit, coffee is a drupe or stone fruit. Coffee processing removes a coffee’s outer layers of skin, mucilage (the pulpy fruit layer of a coffee cherry), and parchment (the protective layer surrounding each bean) after harvesting and before exporting. After the coffee cherry is picked, the pit or seed is fermented and dried using several different processing methods, drastically impacting the flavors.
Alma Family Farms, Finca Terrerito in Copan, Honduras
The washed process or fully washed process requires the coffee seeds (beans) to be removed from the outer layer of the coffee fruit (exocarp) and soaked and fermented in water for several (~12) hours. Water helps remove a sticky mucilage layer (fruit) from the coffee seeds. The seeds are then dried by laying out to sun dry or using a mechanical dryer to take the moisture content from 40% down to ~10-12%. The drying process usually takes 6-10 days.
Drying coffee seeds at Finca Terrerito in Copan, Honduras
This method generally increases perceived acidity and cleanliness. When tasting, the cup is described as clean, crisp, complex, and lively and often exhibits stone fruit and citrus-like flavors (lemon, lime, orange, stone fruit, tropical fruit) with sweet and floral aromas.
During full natural or dry processing, the coffee seeds (beans) are left to dry inside of the coffee fruit and skin. Generally speaking, naturals take a bit longer to dry than washed coffees. Although weather dependent, it will typically take over two weeks to dry natural processed coffees down to a 10-12% moisture content because neither the skin nor the mucilage has been removed. Once dried, the coffee cherries become shriveled and dark brown, resembling raisins. In some regions, coffee cherries dry on the branches and are picked as “raisins.”
This method usually makes for a very fruity-tasting coffee due to the extended contact time with and fermentation inside of the coffee fruit and skin. Acidity tends to be less “bright, crisp, lively” and more “rounded or balanced” with darker berry-like fruit flavors (blueberries, raspberries, strawberries).
We like to think of honey-processed coffees as the middle ground between washed and natural coffees. First, the seeds are removed from the fruit skin and laid out to dry with the sticky, honey-like layer (mucilage) intact. All or part of the fruit pulp or mucilage can remain on the beans as they dry. These coffees are sweet, like honey, and complex, with various tastes and aromas.
As coffee producers experiment, new and exciting coffee processes have emerged. These are all variations of washed, natural, or honey-processed coffees. Examples include semi-washed, anaerobic, and lactic processes, introducing different yeasts to fermentation, and adding fruits to the drying stage. These methods influence the final taste of the coffee in very different ways.
How Does Roast Affect Taste?
After processing occurs, green coffee beans are sent to roasters worldwide who use heat to transform it into a consumable product. There are three main designations for roast level ranging from light to dark. Lighter roasts are less roasty/toasty tasting and have more raw fruit flavors and aromas intact. Darker roasts have less of the raw, inherent flavors and more roasty characteristics. Think of roast level in relation to roasting marshmallows. A lighter roast is less toasty and has more raw sugar or plant tastes and aromas intact. A darker roast has less raw inherent flavor compounds and more roasty flavor characteristics due to the extended exposure to heat. Medium roasts are a balance, retaining some of the natural flavor notes while having some roasty characteristics.Light roast coffee:
- More perceived acidity
- Highlights the complex and nuanced flavors inherent to the bean.
- Generally lighter-bodied and lively.
- Why drink a light roast? You like a lively, bright, or nuanced cup of coffee. You want to taste the coffee for what it is and how it was grown and processed.
- Combines nuanced flavors inherent to the coffee seeds with roasty caramelized sugars to create a balanced and rich cup.
- Generally offers a balance of chocolate and caramel-like flavor characteristics with soft, nuanced citrus or fruit-like acidity.
- Why drink a medium roast? You like a balanced, smooth, complex, or lively cup of coffee.
- Lower in acidity, which is muted and masked by roast characteristics and further caramelization of sugars.
- Why drink a dark roast? You like a rich, bold, or intense cup of coffee. You love the roasty bittersweet flavors that make coffee taste like coffee. A dark roast makes the perfect companion if you like your coffee with cream or milk.
How Brewing Coffee Affects Taste
The brewing process is one of the most critical steps in producing an excellent cup of coffee. The best quality coffee grown, processed, and roasted specifically to your tastes can be disappointing if it isn’t appropriately brewed. This last stage has two main influences.
Brewing method: Different brewing methods can affect perceived taste. French press or complete immersion methods may taste heavier and richer than pour-over methods. Coffee from a pour-over will taste cleaner and possibly brighter than coffee brewed in a French press. Later in this series, we will dive deep into each brewing method and how to make your perfect coffee cup.
Extraction is a term that refers to the brewing process, which is where soluble flavors from coffee grounds are extracted into the water. We are always looking to get an ideal extraction each time by manipulating brewing variables like our coffee-to-water ratio, the grind size of our coffee, the temperature of our water, and several others we will discuss later in the series.
In summary, coffee is a complex beverage with many factors influencing taste. The four main contributors to how a coffee will taste are the environment it is grown in, how it is processed, its roast profile, and how it is brewed. Do you need to know everything? Absolutely not. Will there always be something more to learn that can help you improve the coffee you choose and the taste of it? Absolutely yes. Better understanding some or even just one of these elements will help you improve your coffee and appreciate it more.