How To French Roast Coffee
French roast coffee doesn’t mean that the coffee comes from France. It means that the coffee has been roasted almost to the point of burning. What you get is a rather dark beverage that has a caramelized taste. The French roast is the darkest available in many places. Coffee lovers who prefer a dark brew mostly go for the French roast because of its easy availability. So how can you French roast coffee to have this great beverage? Let’s have a look.
When the beans are roasted, the chemical properties of the green coffee change. The process also gives coffee its particular taste and can significantly change the taste of the brew. As beans are roasted they change in color- green, then to yellow, tan and finally darker and darker brown. Although you can stop the process at any stage and get a nice cup, the more it roasts the better the taste. We are most interested in the darker color for the French coffee. So the normal process will be followed up to the last stage.
Once you have your beans, you will first have to wash them to remove the fleshy fruit. This is a crucial process since it is here that you will be able to separate and sort the many kinds of coffee beans. In this case, the density differences will cause some to float higher.
The roasting process
In the start of the process, the beans take in the heat and the raw ones are dried to a yellow. If properly done, they will have an odor similar to toast or popcorn.
When the temperatures reach 170°C-200°C (338°F-392°F) the sugars in the coffee beans will begin to caramelize. This process is supported by the increase in temperatures of the enclosed moisture by the skin. In this level it is important that the beans have the appropriate moister content. Without this, they will not be able to caramelize the sugars correct. The caramelized sugars will become less sweet which will affect the brew.
During the next step when the temperatures reach about 205°C (400°F) they will begin to expand to about double their original size and become light brown in the same time period they will lose about 5% of their original weight. At temperatures of about 220°C (428°F), they will lose about 13% more weight and release CO2.
Temperature reaches around 230°C (446°F) and the beans become almost dark brown and take on an oily look. Now to achieve a perfect French roast, the roaster has to be very careful as not to burn the beans. In this level they can be stripped of their desirable flavors leading to a burnt taste. Burnt beans taste nothing like coffee and so they are a waste.
If you are following this process closely then you would know that you are almost finished with the whole process. Now, the goal is to get just the right balance of bitterness and acidity to make up the last flavor profile, a coffee that is not too bitter but also not too strong.
When the process is too light, it will leave high concentration of bitter compounds in your cup. On the other hand, if the beans are too dark, they give a better chocolaty taste. This is why most people prefer this type of coffee.
To have good coffee, the beans must “crack” once, and sometimes twice. It is easy to identify quality of taste by looking at the time the cracking process took place before it was removed from the heat. For the mild, medium-bodied roasts like city, full city and Vienna, you will have to remove them after the first crack and before the second crack starts. To have a perfect French coffee on the other hand, you should wait for the second crack—normally a few minutes away from the burning up. Don’t wait for a “third crack” since it doesn’t exist.
Many roasters hesitate to subject their best quality beans to this intensive process since a little of the bean’s flavor make it through. You can still enjoy your beverage by making use of inferior ones that are a composite of different varieties. You need to understand that the bean consistency rarely impacts the flavor of your French coffee.