The Art of Feeling Out Coffee for Sample Roasts

June 10, 2018 Guest User

Follow Your Heart

Before firing up your roaster, before considering different roasting profiles, you must first understand your sample bean and how to draw out all the complex through the roasting process. In general, the quality of a coffee is based on three main factors: sweetness, acidity, and body.

Below is a rough concept that explain the summary of roasting process.

Of course, the flavor itself and lack of defects are also key factors for determining a coffee bean’s quality, so we must understand the “Standard Roasting Profile” for each bean in order to produce the standard flavor notes for a cupping session.

According to the SCA, a “Standard Roast” will result in Agtron color grade numbers 63 for coffee ground coffee. Note: the whole bean should be around 58.

Whole bean Agtron 58 was a standard but not what has been removed. Before roasting, you must also remember that coffee is a natural product and roasting profiles may vary depending on the coffee variety, density, and moisture content. We may also consider the altitude where the coffee was grown.

For example, when roasting a bean with lower density, you might consider adjusting your initial roasting temperature, or “charge temperature”, slightly lower than you might for a denser bean (all other factors being basically equal) to achieve the same results for roasting level.

While these factors are very important, we should also consider some other characteristics that might help you to better understand your bean during the roasting process. These factors include the color, smell, and sound.

While you might focus on the time, rate of rise, and all the other factors we normally consider while trying to achieve a “Standard Roast”, you should also become more comfortable “feeling out” your roasts, which can also produce some very nice results.

While you can “feel out” coffee beans to achieve a nice, even “Standard Roast”, replicating results is one of the most crucial skills for any roast master.

Consistency over many batches ensures that cupping results will be mostly the same.

However, we must also remember that roasting is an art, and letting the beans “talk” to you is also an important for developing your own style as a roast master.

Let’s consider a practical example. We have received a sample of aStrictly Hard Bean (SHB) Specialty Caturra from Guatemala.

The moisture content is a healthy 12%, and the bean has a good density. We are working on a 100g sample roaster, so we decide to set the charge temperature at 185 Celsius on a full flame. We expect this roast to finish around 8 minutes.

However, some factors might change from year to year, and the following year we may find that the yield of these beans has dropped 40%, resulting in a higher density green bean. In this case, we would expect the roast time to be longer.

And this is why it’s important to “feel out” your sample beans! After we have dropped the beans into the roaster, we will observe the beans taking on a yellowish color, which is a sign of the dehydration phase of the roast, and then a cinnamon color until first crack.

Once we reach first crack, we will reduce the flame to about 75% power. This will help to stabilize the temperature and improve the development of the bean flavors.

During this “development phase”, it is easy to destroy the specialty flavors if the flame is too high; conversely, if the flame is too low, we may end up with a “baked” coffee that is also lacking in the specialty flavors of our sample bean.

After first crack ends, we will observe that the coffee is “silent” again, at which time we should check the color again, and after a few seconds (no more than 10), we should find that our bean has reached the target colors for a “Standard Roast”.

The result in the cup should be balanced with even sweetness, acidity, and body.

(Note: In general, master roasters will prefer a darker roast for espresso and especially milk coffees, as the darker, oilier roasts tend to have bolder sweetness and mix well with milk.)

You may have noticed that I did not spend too much time covering traditional roast indicators, such as “turning point”, “rate of rise”, but rather focused on color and sound.

I hope that I was able to provide you, my fellow coffee lover, with more “soft” skills to roast, rather than relying on too many instruments or metrics.

Don’t misunderstand me—these are absolutely important and useful for any roast master. But I also want you to understand that “feeling” out your coffee is another great way to roast and understand your coffees.

So feel it out, and enjoy!