The roaster must learn how to select qualified raw coffee beans and screen defective beans.

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This article provides tips for those who have a knowledge of heavy coffee, or those who plan to be a bean baker, to buy raw coffee beans. It takes patience to pick beans.

Author = Han Huaizong

The quality of high-quality coffee extracted from shell beans must be distinguished according to the bean's (1) defect level (2) bean body length and width (3) altitude (4) cup quality before export. Among them, the most labor-consuming and seriously affecting the cup measurement is the statistical work of the proportion of defective beans. The international commonly used raw bean grading system includes "American Fine Coffee Association Raw Bean grading system" and "Brazilian Raw Bean grading system". The former is suitable for fine coffee and the latter is suitable for bulk commercial beans.

The raw bean grading system of the American Fine Coffee Association increases the deduction points for the major defective beans that seriously affect the cup test, and adopts a tolerant attitude for the defective beans that slightly affect the cup test. The so-called major defective beans refer to black beans, including moldy beans, worm-eaten beans, rotten beans, smelly beans and other dark raw beans. In addition, there is a kind of unripe beans, that is, the so-called "Quaker", which is also the key crime after the division of this grading system. The size of "Bai Mu Dou" is not much different from that of mature beans. If you do not look carefully, it is not easy to distinguish. It is characterized by abnormal green or grayish green, and the surface wrinkles of beans are obvious. It is not easy to find them in raw beans, but it is easy to pick them out after baking. Because underdeveloped immature beans are not easy to be colored by heat, the color is very light, and each furnace will have more or less beans of this kind of color that are very obnoxious to destroy beauty. If it is not picked out beforehand before baking, be sure to pick out these uncolored "white beans" after baking, lest a small number of sour and bitter unripe beans spoil a batch of good beans.

The key to buying raw beans by ●: smell, see and touch

Although coffee from the origin has been checked, accepted and graded before it is exported, in principle, the higher the grade, the fewer defective beans, but it is still difficult to prevent the leakage of bad beans mixed with them, so don't forget to watch its color, smell its taste and touch its quality before buying raw beans.

First check to see if the beans are the same size, which is related to the uniformity of baking. If the size is not evenly mixed, it means that the classification is rough. In principle, the bean size of buying 18 mesh is mostly between 17 and 18 mesh, while that of buying 16 mesh is between 15 mesh and 16 mesh, with a drop of at most one eye. If the difference in size is too big, it is not boutique.

Then take a look at the bean color. Washed beans should be blue-green or light green. If the color is different, there is something wrong with the drying process, the bean body appears markings or the edge is lighter or whitening, this is the damp bean, easy to breed mold. If the whole green is white or faded, it is uneven in dryness. it may be that after washing the coffee, when it is moved to the bean drying farm, the layer is too thick or forgot to turn the beans up and down, resulting in uneven drying or dampness, which tastes like soap. Bleached or faded beans may also be caused by oxidation or contamination. Of course, raw beans have been stored for too long, the water content is too low, and they may fade from blue-green to withered, although they are easy to bake, but they lose all their flavor. And look at the shape of the beans. If the beans are different, it means that they are mixed with other varieties, the most common is that katimo is mixed with Tibica or bourbon beans to make a profit, and it is not a phenomenon of boutique grade. As for the amount of silver skin attached to the bean watch, it doesn't hurt. Sun-dried beans will have more silver skins than washed beans.

After seeing the bean color and bean appearance, you must smell it. Fine beans have a sweet aroma, but over-fermented or improperly preserved raw beans can have pungent chemical, musty or miscellaneous smells. Finally, pick up some raw beans and feel the quality of the beans 142; if it is too hard and brittle, it is easy to break, it means that the temperature is too high when the machine is dry; if it feels soft and tender, it means that the drying treatment is not enough, the moisture is too high, and it is easy to catch mold to turn white or dark. To put it simply, the beans that "look neat, smell pleasant, and touch the head" are the best beans.

Before buying beans for baking, be sure to check them again to get rid of abrupt beans or debris. Although the work of picking beans before baking is time-consuming, there is a lot of fun, such as corn, rice poles, small stones, dried branches, broken leaves, pepper, insect corpses, and shell casings. You might as well take it into the private "bean picking museum". You can also feel the alternative "regional flavor" of planting land! As soon as it comes out of the oven, pick the beans again and pick out the "white beans" that are not easy to color, and the work is done.

Han Huaizong

Works: "New Coffee Science: secret History, Fine beans, introduction to Nordic techniques and roasting" ─ 2014 "Fine Coffee Science: shallow roasting, single, Manor Bean ── the third Wave of Fine Coffee Encyclopedia" ─ 2012 "Fine Coffee next: cup Test, Taste Wheel, Golden Cup guidelines for ── Coffee glutton introduction to Coffee Science" ─ 2012 "Coffee Science: secret History, Fine beans, and introduction to roasting" ─ 2008

"Starbucks: the Legend of the Coffee Kingdom" ─ 1998 "long live Coffee: how small Coffee changes the World" ─ 2000

Content source = "New Coffee Science"