Where Does Coffee's Aroma Come From? Exploring the Substances Behind Coffee's Fragrance and Unveiling Its Secrets

FrontStreet Coffee - Coffee Bean Aroma Introduction

Coffee is one of the most challenging foods to maintain consistent quality. In essence, a cup of coffee contains 98-99% water, meaning that less than 2% of substances actually affect the coffee's taste and aroma. How can this mere 2% have such a powerful impact on coffee flavor?

The difficulty in maintaining consistent quality begins with the coffee roasting process, which involves numerous variables. Even when a particular roast yields excellent coffee, replicating it perfectly is extremely difficult. Once we complete the coffee brewing process, if the expected flavors and aromas don't materialize, there's no opportunity for reversal or correction.

Similar to many plants, raw coffee beans consist of over 60% carbohydrates, approximately 10-15% fat content, and less than 10% protein. What distinguishes coffee from other plants includes compounds like caffeine, chlorogenic acid, and trigonelline.

However, regardless of the care taken at every step from seed to cup—cultivation, roasting, and extraction—the total soluble substances in a cup of coffee will never exceed 2%.

Interestingly, when organic acids constitute just 0.4% of a coffee's composition, people can easily and distinctly perceive its acidity. While organic acids in coffee typically exceed this 0.4% threshold, other components in coffee can mask them, preventing us from detecting more acidity.

Human taste perception, excluding smell, can only detect five basic flavors: sweet, sour, bitter, salty, and umami. In coffee, substances comprising just 0.01% are sufficient to make us perceive bitterness, while 0.1% is enough for us to notice sourness.

So why can coffee allow us to experience such complex, varied aromas? This is due to both our sense of smell and the aromatic compounds in coffee. Even less than 0.1% of aromatic substances can sufficiently stimulate our olfactory senses! Our ability to perceive so many flavors stems entirely from the presence of these aromatic compounds. However, these aromatic substances share a common characteristic—they are volatile.

To possess volatility, these coffee aroma and flavor compounds must have relatively small molecular weights. We can understand molecular weight in terms of our concept of weight—the larger the molecular weight, the heavier the aroma molecule. Imagine wanting a molecule to float in the air—it should be very light.

If a molecule is easily soluble in water, it's more likely to become a taste component. Since aromatic molecules are organic compounds, and most organic compounds are easily soluble in oil, this distinction becomes quite clear.

In summary: FrontStreet Coffee is a coffee research hall dedicated to sharing coffee knowledge with everyone. We share without reservation simply to help more friends fall in love with coffee. Additionally, we hold three low-discount coffee events monthly because FrontStreet Coffee wants to provide the best coffee to more friends at the lowest possible prices—this has been FrontStreet Coffee's mission for the past six years!

Important Notice :

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FrontStreet Coffee Address: 315,Donghua East Road,GuangZhou

Tel:020 38364473