How to Create a Roast Profile

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I am beginning the process of creating a roast profile for the newly arrived Ethiopia Konga. For me this is the most fun part of my job. For those reading this it might be the most boring blog ever.

The first thing that happens is we receive a ½ pound sample of the coffee along with several other coffees. We then put the coffee through a series of tests. The Konga received a low grade for the quality inspection. Which means it is not the cutest bean you will ever see. Then we do a sample roast. A sample roast is done uniformly so all the beans have a basis to be compared to. This was when we came to the OMG moment and said we gotta buy this one!

Several weeks later the bags were delivered. Now we start the process of creating a roast profile. A roast profile is developed to bring out the best of the inherent flavors in the bean. Then it is written down so that the process can be repeated and create the same flavor profile each time it is roasted.

For the first round I will roast 3 pounds of coffee to 3 different levels (medium, dark and extra dark). All the while we are trying to reach set parameters during the roast and recording time, temperature, gas pressure and air flow.  We let the coffee rest overnight before we taste the different coffees.

After tasting the three roasts we decide which is the best direction for us to go. Once we decide on the degree of roast is best then we will roast another 3 sets of 3 pounds. This time we will vary the time it takes to get first crack from 9, 10 and 11 minutes. The cracking noise is when the center membrane of the bean breaks and one will hear an audible crack. Then to the time when we will finish the roast which is called the drop. Typically we want to drop the beans 3 minutes after the first crack regardless of the temperature we are going to roast the bean. We do this by adjusting the gas pressure and air flow. We let these coffees rest overnight before we taste them.

The next day we will decide which roast tasted the best. Then we will take note of what is overpowering and what is underdeveloped in the coffee. Using different techniques we can accentuate the positive and diminish the negative. We then take another 3 sets of 3 pounds to fine tune the roast profile.

So far the Konga has proved to not want to be like the others. The first crack starts 10 degree lower than the others. Slowing the bean down so that it takes a full 3 minutes till the drop temperature has proven to be difficult because the temperature increases way to fast. I am very sure that the end result will be something spectacular.

 

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