How to understand the relationship between coffee roasting curve and taste

In Europe at the beginning of April. Seven bakers bake Costa Rica with the same machine and the same baking degree. Tarasu. In terms of techniques, they are all different, at least in details, so who is right? Everyone has to go back to the cupping desk for answers. Some people adjust the fire three times after an explosion to change the curve, while others are slightly dull and adjust only once until the end.

The second important point about coffee roasting is the understanding and understanding of raw beans, which is a bit like those who use traditional film cameras to learn photography, whose grades are piled up by film, so a good roaster is piled up by the amount of raw beans baked. Therefore, Uncle Dou does not recommend learning to bake with the mentality of playing and watching, because various reasons indicate that there is no quick road.

Some friends may think that Uncle Dou is playing tricks here when they see this, but Uncle Dou really tells you that this is what I really learned. Well, Uncle Dou understands that coffee roasting should be practiced from three levels: first, understanding utensils, second, understanding coffee, third, understanding taste, these three levels are not isolated but interact with each other and improve each other.

With the increase of coffee bean surface temperature and the decrease of the temperature difference between bean surface and bean core, a considerable proportion of water has been dissipated in this process. If you look at the sample in the sampling rod at this time, you will find that a light yellowish brown begins to appear, and then look down and smell it, and the original pure smell of hay is replaced by a hint of sweetness, which means that the time has come for chemical reaction to dominate baking. At this time, we should give enough heat supply so that a large number of chemical reactions that need to absorb heat and produce charming flavor can be carried out smoothly. It is precisely because of the addition of a large number of endothermic chemical reactions that the temperature rise slope of coffee beans we have observed began to slow down.

With the continuous absorption of heat, more and more volatile gases (mainly water vapor) accumulate in the coffee beans, which causes the pressure inside the beans to far exceed the external atmospheric pressure, even reaching 25 atmospheric pressure (2533 kPa). The internal pressure is so high that it is like a small bomb that is finally enough to tear the structure of the raw coffee beans. This critical moment is called First Crack.

In a sense, as long as there is an explosion of coffee beans, they can be cooled, ground and drunk, but it is still a very shallow baking degree, which may not be the best baking degree we want. Next, we should pay close attention to the stage of roasting, observe the color of coffee raw beans by sampling, smell the aroma changes of coffee raw beans, find the best baking degree, and then cool it decisively. We know that the ingredients in raw coffee beans are in the following order: sugars, moisture, fatty substances, proteins, acids, minerals, alkaloids (such as caffeine) and other volatile aromatic substances. The content of these substances essentially determines the flavor of a cup of coffee drink.