When having your delicious cup of coffee in the morning, you may wonder how the coffee was made. It all comes down to the important process of roasting. What you need to know is that roasting coffee is not always an exclusive privilege of a pro. If you are thinking of taking up a new hobby, coffee roasting at home can be an interesting and enjoyable choice. This article will help you go through the roasting process, including the equipment and materials needed for home coffee roasting, and introduce you to several roasting profiles that can deliver different types of roasted beans.
What is coffee roasting process?
Roasting is the process of transforming chemical and physical states of coffee green beans into fragrant and dark brown beans. The roasted beans are then ground to be ready for brewing.
Different types of beans deliver different results
Coffee beans are grown in warm climate areas. The countries which are located near and around the equator are the main coffee producers. Today, two prime types of coffee beans widely commercialized are Arabica and Robusta. Arabica beans are mainly grown in the Western hemisphere with Brazil and Colombia as the two largest Arabica beans producers. Robusta beans are mainly grown in the Eastern Hemisphere with Vietnam, Indonesia, and some African countries as the leading producers.
Arabica beans are known to offer a smoother and sweeter taste. It also has “larger” range of aroma with taste and smell of chocolate, fruit, and sugar. In terms of shape, Arabica beans are more oval. The trees are grown in highlands areas which are 1,000 – 2,000 meters above sea level. Robusta beans offer a strong, bitter, earthy, and grain-like taste. It contains nearly double the caffeine compared to Arabica beans. The shape of a Robusta bean is more circular.
You need to know what type of bean you are going to roast as each type of bean requires a different roasting method. You may want to have a blend of both Arabica and Robusta in your coffee. The roasters usually prefer to roast them separately while some professional roasters I know like to put a blend of both types of beans into one batch.
How do you want your coffee beans to be roasted?
Now let’s talk about the fun part – the roasting itself. Basically speaking, coffee beans are roasted in a high level of heat from 370oF/190oC to 420oF/215oC. You can roast the beans traditionally by using a frying pan, the way our ancestors did dozens of century ago or by using an automatic roasting machine like most of us are doing today.
Remember that the taste of your coffee is affected by the two most important factors in roasting process: degree and time. You will need to control how much heat and for how long your coffee beans are roasted. For any type of beans, there are three major types of roasts which you can apply to your home coffee roasting according to your preference.
- Light roast
Light roast beans are light brown in color. There is no oil to be seen on the surface of the bean. The bean is heavier as it has not been much steamed and dried. Since there is not much of a chemical transformation, the original taste and flavor of the beans are most retained in the process.
Generally, the internal temperature used in the process is from 356oF to 410oF (180oC to 210oC). With this temperature, the bean cracks (known as “first crack”) and turns its color.
- Medium roast
These beans are brown in color. Similar to light roast, there is no oil to be seen on the surface of the bean. As being more dried and steamed, the bean is lighter in weight. With this roast style, the taste and flavor of the coffee is balanced. You can notice the aroma of the coffee in this stage.
The temperature range is from 430oF to 445oF (201oC to 230oC). The bean cracks and known as “second crack” in this stage.
- Dark roast
These beans are dark brown, and some are black in color. Oil is seen on the surface of the bean. The dark roast coffee is rich in flavor and taste. You will easily smell the pleasant aroma of the coffee. Dark roast is preferred by coffee drinkers who want full-body taste and richness of flavor.
With the temperature from 465oF to 480oF (240oC to 250oC), the coffee bean is the most dried and steamed.