How Coffee Aroma is Developed - The Rich Fragrance of Coffee Beans Comes from Technical Roasting

A coffee bean does not carry its aroma from the tree. Everything we smell and taste in the cup is created, or unlocked, during roasting. Understanding which compounds are responsible makes it much easier to understand why roast level changes a coffee so completely.

FrontStreet Coffee: Where Coffee Aroma Comes From

Acids and Sugars Determine Coffee Flavor

Acids Influence Coffee Quality and Complexity

Coffee beans naturally contain acids such as citric acid and malic acid, along with some acetic acid formed when sugars and other compounds break down or react. The quality and the complexity of a cup depend on the balance of those acids in the bean.

Chlorogenic acid, a group of polyphenolic compounds, decomposes during roasting. The caffeic acid and quinic acid it yields can also contribute complex bitter and sweet notes when they are present in low concentrations.

Sugars are the Main Source of Coffee Sweetness

Sucrose is what gives the finished cup its obvious sweetness. During roasting, sugar components break down, which is exactly why a dark roast tastes more bitter than a light one.

As roasting proceeds, caramel molecules undergo caramelization and react with proteins in the Maillard reaction, browning the beans and generating large amounts of aromatic compounds. Caramelization is behind the aromas of caramel, butter sugar and vanilla.

The Maillard reaction is responsible for roasted flavors, floral notes, spice and chocolate.

The sucrose content of a coffee bean peaks when the fruit is fully ripe, which is why buyers visit growers in autumn to make sure pickers are taking only fully ripe cherries.

Alkaloids Make the Coffee Flavor Profile More Complete

Caffeine belongs to the alkaloids, and so does trigonelline. Caffeine is bitter, and bitterness is part of the overall flavor. Trigonelline is bitter as well, but it helps aromatic compounds form.

Trigonelline breaks down during roasting and often becomes niacin, or vitamin B3.

All These Flavor Sources Depend on One Thing: Roasting

Roasting is a familiar word to pastry chefs and bakers too. It is during roasting that the true aroma and flavor of coffee are generated, mainly through caramelization and the Maillard reaction.

One more term is worth knowing. Melanoidins are products of the Maillard reaction, formed when amino acids meet the carboxyl groups of reducing sugars. They are large molecules, and they are the substances that turn coffee beans brown.

Conclusion

In short: FrontStreet Coffee is a dedicated coffee research establishment that is glad to share what it learns. We hold nothing back because we want more friends to fall in love with coffee, and we keep studying the roast to understand where flavor really comes from.

FrontStreet Coffee Recommendation

Roast level is the lever that decides which of those compounds dominate, and the medium roasts are where balance lives. FrontStreet Brazil Queen Estate is a good starting point. It comes from Brazil, the world's largest coffee producer, and its rare Yellow Bourbon variety is roasted medium so that cream peanut, chocolate, toasted bread and sugarcane come forward with sweetness rather than bitterness. For a darker, sweeter cup, FrontStreet Strawberry Candy Geisha Blend combines two origins, a honey-processed Costa Rican coffee and a washed Panama Geisha, and the medium roast preserves the floral and fruit of both while adding a soft roasted aroma; it suits a cold brew, a pour-over or an espresso.

FrontStreet 2013 Yunnan Natural Typica rounds out the group as a Chinese single origin, grown on our own estate and roasted medium to bring out its balanced, gentle character, with nut, brown sugar, black tea and dried apricot, and enough flexibility for a pour-over, a cold brew or an American-style drip machine. FrontStreet Jamaica Blue Mountain No. 1 makes the case for balance at the top of the range: the Typica grown in Jamaica is roasted medium so that acidity, bitterness, sweetness and aroma knit together into an elegant whole, delivering chocolate, roasted nut, cream and caramel the moment it hits the tongue. Read together, the four show how a single decision at the roaster shapes everything downstream.