Orignal article from Bellissimo Coffee Advisors

Green coffee beans are roasted, so that they are transformed into actual coffee products. The roasting process is responsible for the differences in taste and aroma, allowing one to enjoy a wide range of flavors (earthy, sweet, and floral). Both the style of roasting and the degree to which the coffee is roasted play a role on the ultimate coffee flavor. 

If you are interested in roasting your own coffee beans, there are a few factors to take into consideration. These include, among other things, the rate of rise, airflow, temperature, development and roast style (along with the associated flavor). Keep on reading and discover more information on these factors, as well as on how to obtain the perfected roasted coffee.

1. Rate of rise

In the simplest of terms, the rate of rise refers to the speed with which the bean temperature increases. According to TryCoffee, this should be measured every thirty seconds, as it will offer excellent control over the roasting process. It is important to take this into account, as you will be able to manipulate the roast to your desire and achieve the roast profile you wanted.

For the perfect roast, you should perform the recommended measurement, until you observe the rate of rise slowly decreasing. If the rate of rise remains unchanged or digresses, this can lead to a baked flavor, which is quite unpleasant. You should also avoid the rate of rise increasing too much, as this can take the sweetness out of the coffee.

2. Charge temperature

The charge temperature is an essential factor to consider when roasting coffee. This refers to the drum temperature, just before the coffee is added and it can influence the whole roast profile. Roasting means that the heat will spread to the beans, so it is clear why controlling the temperature is a must (especially if you are looking for a specific flavor to be obtained).

If the charge temperature is too low, then it is possible the desired flavor will not be obtained (poor flavor development). You might end up with a baked or flat coffee flavor, which is not something to be desired. The only situation, in which a lower charge temperature is acceptable, is when you are trying to control the acidity of your coffee. Always adjust the temperature in accordance to the types of beans you are roasting.

3. Airflow

A dynamic factor to be considered, the airflow influences the final flavor of the coffee, in equal percentage with the roasting time and temperature. If the airflow is not kept under control, you will risk obtaining a flat or baked flavor; moreover, you might also find the roasted coffee to be either dull or dry. 

The roasting process is finely tuned by the use of the right airflow, in combination with the heat. These two factors allow you to control the roasting process. The higher the airflow is going to be, the better the heat will be transferred to the beans. You should increase the airflow gradually throughout the roasting process.

4. Development

The development of the coffee bean is important throughout the entire roasting process, starting with the initial stages. You should never mistake the development for the actual color; just because the coffee beans are darker, this doesn’t mean they are properly developed. 

The solution is to apply an even amount of heat, so that the coffee beans develop both on the inside and outside, with a rich flavor in the end. Underdeveloped coffee beans are dull, while the overdeveloped ones can have undesirable flavors as well. Opt for correct development and you will have just the right flavor, intense as ever.

5. Roast style

There are various roast styles out there, with each leading to the achievement of a unique flavor. For example, there is the cinnamon roast, which bears this name as the roast style reminds of the actual spice color. Each roast style has its own set of features – for example, the cinnamon roast is a simple roast, with a less intense aroma.

Other roast styles include the espresso roast, medium roast, light medium roast and light roast. The trick here is to explore each different type, discovering the flavor obtained and comparing it with the others. When it comes to roasting coffee, an essential thing is to be willing to practice, playing with roasting styles, roasting times and coloration.

In conclusion, these are some of the important factors to take into consideration when roasting coffee. As you will see for yourself, practice makes perfect. The more you explore the roasting process(es), the easier things will become and you will be able to enjoy yourself to the fullest. 

Do you want more help with your coffee business? Bellissimo offers one-on-one consulting services no matter what stage you are at in specialty coffee.