Seven Key Factors Influencing Coffee Aroma and Flavor: Bean Varieties, Growing Environment, Roast Level, Processing Methods, and Brewing Techniques

As coffee enthusiasts, we know that coffee can show an incredibly wide range of character. From earthy tones to sweet fruity notes, floral aromas and tea-like qualities, our beloved beverage offers remarkable taste experiences. But what actually determines the flavors that show up in your cup?

There is no simple answer. The science behind coffee flavor is still in its early stages, and we are only beginning to understand what happens at the chemical level. There may be factors we have not yet identified, and no one can say definitively how much each step in the supply chain affects the final product. Even so, there are some important factors we do understand today.

Most coffee enthusiasts could probably name a few of them off the top of their heads. Everyone knows roast characteristics matter, and most of our customers tend to consider origin as well. In this article, FrontStreet Coffee walks through the different reasons coffee tastes the way it does, from the place it is grown to the final step.

1. Variety

Even before the coffee plant begins to grow, one crucial factor affects the crop: variety. This is not as simple as Arabica versus Robusta (we generally recommend staying away from the latter). Within the Arabica species there are dozens of known varieties, with more being discovered and created all the time.

Wine enthusiasts will tell you that variety has a significant impact on what ends up in your glass. Cabernet Sauvignon has very different characteristics from Grenache or Riesling. Coffee works the same way: the variety, or combination of varieties, in your cup will have a major impact on your experience as a drinker.

As Jono from Rosetta Roastery noted on a recent Coffee Brewmance podcast, many coffee enthusiasts may not give this important factor enough thought or discussion.

2. Terroir

Whether you are talking about wine or coffee, terroir is one of those lofty terms that can alienate people, but in reality terroir is simply the influence of where the coffee is grown. We all know Kenyan coffee tastes quite different from Brazilian coffee, and that coffees from nearby regions can share similarities. Those are all results of terroir.

Of course, the specific conditions that make up terroir are numerous and complex, but here are some of the important ones:

• Altitude
• Climate
• Soil type
• Soil microbiome
• Topography

We are certainly not suggesting you need to understand every element of terroir for every coffee you drink, but if you want to understand your coffee better, it helps to know where it comes from and a few defining characteristics of that terroir.

3. Farming Methods

For end consumers, one of the most important and perhaps hardest factors to grasp is that practices on the farm have a huge impact on the taste of the coffee you drink. From chemical usage to planting patterns and pruning schemes, everything ultimately affects the nature of the crop.

One particularly important practice is picking. Like other crops, coffee is best picked at optimal ripeness, but coffee cherries do not ripen uniformly. That means the best results require hand-picking by trained workers who pay attention to the ripeness of the fruit they harvest.

Commercial-grade coffee is typically strip-picked (all the fruit on a branch taken at once) or machine-harvested, which leaves the final product a combination of ripe and unripe fruit. That is cheaper, but it does not produce high-quality coffee.

Other Resources:

• Wikipedia article on coffee production: https://en.wikipedia.org/wiki/Coffee_production
• The Perfect Daily Grind: Specialty vs. Commercial Coffee

4. Processing

Once cherries are picked, the coffee seeds must be dried before they can be transported and eventually roasted by local artisan roasters. How that is done varies enormously and has a tremendous impact on the final taste. It is a complex topic in itself, but here are the main categories to know.

Natural or Dry-processed Coffee

Natural, or dry, processing is the traditional method in Africa. The coffee is actually dried while still inside the fruit. The advantage is that it does not need large amounts of running water, and more of the coffee's natural sugars penetrate into the roasted beans. Naturally processed coffees tend to be fruity with lower acidity, though they are sometimes found to have less clarity.

Although this method can be more economical, it carries a higher risk of the crop spoiling, and the cherries must be turned by hand frequently to reduce that risk.

Washed or Wet-processed Coffee

This more modern method simply ferments the cherries and then removes the seeds from the fruit, or pulp — the "washing." Its advantage is that taking off the outer fruity layer removes some risk of spoilage.

Washed coffees tend to have higher acidity and greater clarity, which is exactly why they are so popular in the third wave of coffee.

Honey Processing and Everything In Between

Recognizing that both wet and dry processing have their benefits, a third family of methods emerged to balance the two. Put simply, honey-processed coffees have some, but not all, of the outer layers of the fruit left on during drying.

There are many styles of this kind, usually named after the color of the final dried crop — yellow, red, black — and in most cases they simply involve removing different amounts of the external mucilage.

Note that not every processing method falls neatly into these categories — see the additional resources below.

5. Roast Level

We may be on more familiar ground here, but that does not mean we should overlook the impact of roast characteristics on flavor. Even the most talented roaster cannot take inferior green beans and make them taste delicious, but an unskilled roaster can certainly ruin many good ones.

After sourcing and selection, the roaster realizes the coffee's full potential by carefully crafting a roast profile suited to that particular lot. This is not as simple as light or dark — roast color, in fact, can be misleading. The roaster has to fine-tune variables such as roast time, charge temperature, rate of rise, drum speed, airflow and cooling speed, while responding to data such as temperature logs and first and second crack times, and, most importantly, to sensory experience.

6. Blended Flavors

Decades ago, most of the coffee drunk in the world was blended. That may still be true across the industry as a whole, but in the specialty world, single origin is becoming increasingly popular — likely because it lets drinkers experience the fruits of the coffee farmer's labor, quite literally.

Even so, blending itself can be an exquisite craft. In its basic form it ensures a more consistent flavor experience year-round as the component coffees change with the seasons. At its best, a blend can be a unique taste experience in which the flavors amount to more than the sum of their parts.

7. Brewing

Last but certainly not least, brewing is the final stage of the soil-to-sip journey and has an important impact on flavor. A mistake new enthusiasts often make is assuming that exactly the same brewing parameters will give the best results in every coffee. "What is your AeroPress recipe?" is surely a common question among beginners.

Any barista will tell you that your brewing variables need to match the coffee you are brewing and the method you are using. With espresso, they may even need to be adjusted for environmental conditions such as temperature, humidity and altitude. Even in simple manual brewing, small variations in the variables can be the difference between decent and delicious.

Some important variables are:

• Brew ratio (water to coffee)
• Grind size (and uniformity)
• Extraction time
• Water temperature

FrontStreet Coffee Recommendation

If the seventh factor is the one you want to work on, the answer often lies in the beans you choose to brew a latte with. The FrontStreet Classic Blend is built for espresso and moka pot use, and its greatest strength is crema: even a beginner on a non-professional home machine can pull a dense, fine crema. Based on the classic Mandheling-Brazil combination and roasted dark, it keeps the dark chocolate, nut and caramel notes coming through, and the full, mellow body works for lattes, cappuccinos and Dirty coffee alike.

For a nuttier, more milk-friendly cup, the FrontStreet Premium Blend leads with Brazil, so a latte shows complex almond and walnut notes with a silky, lingering texture, while the FrontStreet Black Cocoa blend — 100% Arabica — is the value-oriented choice with plenty of crema and a full body at a friendly price. If you prefer a fruity milk drink, the FrontStreet Strawberry Candy blend is a fruit-forward espresso blend that reproduces a distinct strawberry soft-candy sweetness, and it works for a home or a cafe menu that wants something different from the usual.