Roasting Coffee Beans
Learn how coffee beans are roasted to get their rich aroma and flavor.
Coffee beans are green in color. They need to be dried and then roasted to process them into the coffee beans that we use for our beverages. This article elaborates on the process of roasting the dry coffee beans.
The machine used for roasting coffee beans is a huge, heated rotating drum which looks like a hot air popcorn popper. The beans are roasted in a series of stages closely monitored to ensure that everything proceeds smoothly.
The first 5 minutes of roasting serves to evaporate the moisture within the beans. the green beans slowly change color to become yellow beans. The oily, buttery smell of the natural oils within the beans is emitted. The next stage of roasting is to dry the beans until they pop; like the way popcorn pops when roasted. The yellow beans become drier and they become dark yellow and then brown. By now the beans would have expanded to double their original size.
When the beans are light brown, they have lost a lot of their internal moisture. Some commercial coffee makers consider the roasting process as completed. Other coffee processors want to dry the beans more to get a richer aroma and flavor. For this, the beans are dried until they become dark brown and also secrete their oil.
After sweating out their oil, the beans are truly dry and give out a second pop. This signals the end of the roasting. By now, the beans have lost about 20 percent of their original weight. For light coffees, the loss in weight after roasting is only about 10 percent. The richer coffees are made at a loss of 20 percent of their weight. This accounts for the price difference for expensive coffees.
The dry coffee beans are cooled by pouring them onto a cooling tray. Care is taken to dry the surrounding air so that moisture does not condense onto the hot beans and dampen them again.
Every coffee maker has his own trade secret of roasting coffee beans. The process needs to be meticulous to preserve the integrity of the coffee beans. Once a mistake is done, it cannot be undone and that batch of roasted coffee beans is ruined.
You may be curious enough to want to grow your own coffee tree and harvest your own beans to process. Due to the various stages of drying and roasting the beans, there is substantial loss in weight and you eventually end up with only a fraction of what you started off with. Thus, making your own coffee is only feasible if you have a large quantity of coffee beans.
Every coffee tree produces a different yield of coffee beans depending on the climate and harvesting conditions, The roasting process and duration of each stage of roasting will also vary in accordance with the amount of moisture within that yield of coffee beans. After so much trouble, you'll appreciate every cup of a good coffee brew.