Is the Roasted Aroma Exclusive to Dark Roast Coffee? How to Describe Coffee Aroma Like a Professional

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FrontStreet Coffee - Introduction to Coffee Aroma Sources

Coffee beans undergo various changes during different roasting stages. When green coffee beans absorb heat, their color begins to change from green to yellow, and the moisture content of the beans starts to decrease. Heat energy converts the moisture inside the coffee beans into steam → carbon dioxide is produced inside the coffee beans → the internal pressure of the coffee beans reaches 25 bar (pressure unit) → First Crack: coffee beans produce a representative cracking sound during the roasting process.

Flavor development: the longer the roasting time, the acidity gradually decreases while bitterness increases. After dehydration, coffee beans begin to release heat energy and turn brown, while also shedding a layer of silver skin. The volume of roasted coffee beans increases by 1.5 to 2 times, while the weight decreases by at least 11%. Continuing to roast coffee beans will continuously produce carbon dioxide → Second Crack.

The color of the coffee beans deepens, entering the medium-dark roast stage. At this point, the weight loss reaches 22% of the original. After the second crack, the coffee beans surface becomes oily due to pyrolysis reactions and begin to carbonize, which can easily lead to burning if not careful.

During the drying stage, three to four types of aromas begin to develop. The aroma and flavor of coffee are released through two chemical reactions:

• Maillard reaction: when the moisture content of coffee beans is less than 5%, chemical changes occur between sugars and amino acids (produced from protein degradation).
• Caramelization reaction: chemical reactions that occur between water, sugars, and sucrose.

As the roasting time extends, acidity gradually decreases while bitterness increases, and many aromatic molecules begin to volatilize. By the end of roasting, nearly 800 types of aromatic compounds are developed, and the flavor, acidity, sweetness, and body of the coffee beans reach maturity. However, roasting can sometimes bring out undesirable flavors in coffee. In the final stage, aromatic compounds are destroyed, replaced by bitterness, while acidity disappears and body also decreases.

Flavor Description

Flavor description is one of the most intimidating aspects of coffee tasting, and also the most frustrating. When describing flavors, roasters not only describe the flavor itself, such as nutty or floral, but also cover a wide range of sensory terms. For example, a roaster might describe coffee as having mature apple notes, which implies the coexistence of sweetness and acidity.

If you have the ability to identify various flavors, record them; conversely, don't worry excessively. Any words you can think of to describe flavor are useful, regardless of whether they relate to taste.

Knowledge Point

Light roast is characterized by acidity and flavor. If not roasted properly, it can have astringency and irritation, while the body and aftertaste of the coffee feel relatively low.

In Conclusion

In short: FrontStreet Coffee is a research specialty coffee shop, happy to share coffee knowledge with everyone. We share without reservation only to help more friends fall in love with coffee. Additionally, we hold three low-discount coffee activities every month, because FrontStreet Coffee wants to let more friends enjoy the best coffee at the lowest price. This has been FrontStreet Coffee's mission for the past 6 years!

Important Notice :

前街咖啡 FrontStreet Coffee has moved to new addredd:

FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473