What are the effects of roasting on coffee flavor?

Use electric coffee grinder or antique coffee grinder to grind coffee in a pleasant afternoon. Drinking coffee with friends using cute coffee cups and double wall coffee cups is a relaxing thing. One of the most important and influential steps to transform coffee from the state of green beans into cooked beans that can be brewed is roasting! The reason why the coffee we drink is bitter, some with fruit acid, and some with nut, caramel, and chocolate flavors is determined by roasting! Let's take a look at the effect of roasting on coffee flavor.

The main purpose of roasting coffee

The main purpose of roasting coffee is to quickly heat the green beans to produce many chemical reactions. These chemical reactions include thermal cracking, Maillard reaction and caramelization, which will bring aroma and flavor. A similar reaction occurs when baking our favorite bread or biscuits.

The degree of difference between different baking styles is very large, because every brand and every baker has its own unique views, likes and dislikes. Most commercial baking is done in a drum roaster, and the range of roasting depends on the limitations of the machine and the amount of processing the roaster wants.

The process of roasting coffee

The drum roaster is like a clothes dryer, which heats the coffee beans tumbling in the drum through a combination of heat convection and heat conduction. From the time when the green coffee beans enter the drum to the end of roasting of the coffee beans, they are poured into a cooling tray. The whole process varies according to the roaster's requirements and the degree of roasting, but generally takes 10-15 minutes.

The roasting temperature of coffee beans fluctuates during the roasting process. When roasting is nearing the end, the temperature is as high as 232 degrees Celsius. The key to successful coffee roasting is to be able to monitor and manage these temperature changes over time. Once the roaster loses control of these variables, the consistency and quality of each pot of coffee is at risk.

Towards the end of the roasting process, when the taste of the coffee begins to change, the gas formed in the coffee beans will expand rapidly. When they overflow from the beans, they will make an audible popping sound, which we call "first Burst". The first burst occurred at 193 degrees Celsius, which is an important indicator for the roaster. Most light to medium roasted coffee beans finish roasting soon after this burst occurs.

Judgment of baking degree

Knowing the roasting degree or color of coffee beans can help you determine the coffee taste represented by a certain roasting degree to suit your personal preferences. Since the degree of roasting is ultimately determined by personal taste, there is no “best” or “worst”. Specialty coffee roasters are proud to know what degree of roasting will make coffee beans show the best flavor. "Bake the curve" to do this. Instead of relying on ambiguous colors or names, they describe each unique coffee bean with the special taste brought by roasting.

Coffee roasting is a wonderful thing, starting from grinding coffee beans with manual coffee grinder, hand coffee grinder, or commercial coffee grinder, to the fragrant coffee in exquisite coffee cups and elegant coffee pots, this is really a pleasant process.