How Does the Roasting Process Shape Blue Mountain Flavor?

The roasting process sets roughly eighty percent of a coffee's final taste, which is why Front Street designs a specific curve for Jamaica Blue Mountain No. 1. The record runs from a 170°C charge temperature to discharge at 201.3°C, tracking turning point, yellowing point and first crack so heat and airflow stay coordinated.

Blue Mountain beans grade at 17 mesh or above, hold a defect rate below 3% and sit near 13% moisture, characteristics that suit a steadily rising roast. Heat level affects the degree reached and the coffee aroma released, but excess heat also amplifies undesirable tastes, so even development from inside to outside matters more than speed.

Roasting is the core step that determines the direction of coffee flavor. Green beans must be roasted over fire before they can be consumed, and the degree of roasting often influences eighty percent of the final taste performance. This article uses Front Street Jamaica Blue Mountain Coffee as an example, starting from key nodes such as charge temperature, heat adjustment, turning point, yellowing point, first crack, and temperature rise, to analyze in detail the roasting curve design approach for Blue Mountain No. 1 coffee beans. The article also combines specific characteristics of Blue Mountain coffee, such as 17 mesh or above, defect rate below 3%, and moisture content around 13%, to explain why it is suitable for a steadily rising roasting method, and provides a complete operation record from charging at 170°C to discharging at 201.3°C, helping coffee enthusiasts understand how to coordinate heat and airflow to make Blue Mountain coffee present a cleaner, more layered flavor.

Front Street Jamaica Blue Mountain Coffee Roasting Curve

Charge temperature: 170°C

The flavor foundation of coffee comes from roasting. Green beans must be roasted over fire before they can be consumed, and this process is called roasting. After roasting is completed, about eighty percent of the coffee's taste has already been set. The roasting process is quite demanding in operation. If the fire is too strong, it is easy to cause the outside to be scorched while the inside remains underdone; if the fire is too weak, the inside will be overheated. To make coffee beans cook evenly from inside to outside, heat control is the core.

[Heat Level]

The strength of the heat directly affects the final roasting degree the coffee beans reach, and also relates to flavor performance and the required roasting time. When the heat is on the higher side, flavors are released more fully, but what is released is not necessarily all positive flavor. Sufficient heat can prompt coffee beans to generate more flavor substances, but at the same time it also amplifies the undesirable tastes in the beans themselves.

[Turning Point]

After green beans are put into the roaster drum, they quickly absorb heat, and the drum temperature drops noticeably. Then at a certain moment the temperature rises again. The equilibrium position where the temperature changes from falling to rising is the turning point.

[Yellowing Point]

After green beans enter the endothermic stage, heat must be transferred to the inside of the beans, which relies on the conduction of water. If the beans' moisture content is on the low side, the time needed to reach the yellowing point is shorter; conversely, if the beans' moisture content is high, the time to reach the yellowing point is longer. After water evaporates into steam, the steam pressure and temperature inside the beans rise at the same time. At this point the bean body begins to expand, chlorophyll is destroyed, and so the yellowing point is reached.

We also sampled some beans during the roasting process. Let's see what kind of changes this is?

Therefore, throughout the entire roasting process, the use of airflow must be coordinated to adjust the coffee beans' flavor to the ideal state while ensuring the coffee's cleanliness.

Proper caramelization reactions can give coffee greater complexity and layering, bring a fuller body, and impart aromas such as caramel, chocolate, and roasting. Pyrolysis reactions cause those substances that give coffee plant-like flavors to decompose.

[First Crack]

First crack refers to the obvious and intense sound the beans make inside the machine during coffee roasting, similar to the sound of popcorn popping or firewood burning. When the pressure generated by the internal moisture evaporation after the coffee beans absorb heat exceeds the strength of the bean body itself, the cell walls cannot withstand the pressure of the expanding bean center and rupture. At this time the coffee beans make the sound of first crack and simultaneously release heat energy and sound energy.

This is the process by which "first crack" occurs. At this time different flavor compounds are released (that is, aromatic substances such as floral and fruity notes), and browning takes place (which is why coffee beans are brown). This stage is also a period when coffee beans undergo substantial development changes. Dropping the beans just one second earlier or later may produce a very large difference in flavor.

[Temperature Rise]

The temperature difference between two time points, for example there will be a temperature difference between the 2nd minute and the 3rd minute in the figure. Subtracting the former (108.8°C) from the latter (122.4°C) gives a value (13.6°C).

Taking the roasting of [Front Street Jamaica Blue Mountain Coffee] as an example, it is necessary to understand the nature of this bean. Front Street Blue Mountain coffee is No. 1 beans of 17 mesh or above, with a defect rate below 3%, moisture content around 13%, and medium bean density, suitable for roasting with a steadily rising method.

In the process of designing the roasting curve, my personal experience is that during roasting attention should be paid to the fact that the Front Street Blue Mountain roasting curve is suitable for a low charge temperature. The bean density is low, and after first crack the temperature rise should not be too high. A temperature rise below 6 degrees is better, extending the development time.

First, charge when the drum temperature reaches 170°C, set airflow to 3, after 1 minute adjust the heat to 140°C, keep airflow unchanged, roast until 5'10", at 153°C the bean surface turns yellow, the grassy smell completely disappears, dehydration is complete, adjust heat to 115°C, change airflow to 4;

At the 8'00" minute, the bean surface shows ugly wrinkles and dark streaks, and the toast smell clearly turns into coffee aroma, which can be defined as the prelude to first crack. At this time you must listen clearly for the sound of the first crack point. At 8'12" first crack begins. Reduce the heat to 90°C, fully open the airflow (adjusting the heat must be done very carefully, and it must not be so low that there is no crackling sound), and discharge at 201.3°C.

The above content is compiled by CoffeeHunters, a coffee news website.