Understanding what is coffee defective beans classification of defective beans how to select defective beans

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A brief discussion on the definition of "Coffee defective beans" by the American Fine Coffee Association (SCAA)

Basically, after the seeds produced by healthy coffee trees are removed, they are washed, sunburned, fermented, dried and shelled. The whole post-processing process is flawless. The color of coffee beans should be blue-green, light green or yellowish green, which are healthy and delicious colors. If there are other harmful colors or spots, it is a warning of defective beans. Because the precursor aromatic components of defective beans-protein, sucrose, fat, trigonelline and organic acids-are oxidized or eroded by molds and fungi, the color of the beans is strange, so since the chemical composition has deteriorated, the color and smell of the coffee will not be good. Drinking it may be harmful to your health.

Coffee production from cultivation, fertilization, irrigation, picking, peeling, fermentation, drying, shelling, transportation and other post-processing to storage, are all variables, the slightest carelessness will deteriorate into defective beans. According to the statistics of the International Coffee Organization (ICO), on average, about 15% to 20% of defective beans are produced in the world-black beans, fermented beans, moldy beans, moth-eaten beans, wilted beans, unripe beans, shell beans, shell beans, broken beans, floating beans, etc., which will cause animal flavor, rotten fruit, bleached water, iodine, sour, potato, fishy, rotten wood and miscellaneous bitterness in coffee, and may contain biotoxins. It's bad for your health.

According to the statistics of the International Coffee Organization (ICO), there are about 1.5 million metric tons of defective beans worldwide in a year. Defective beans will be consumed by the producing countries or transferred to low-cost formula beans to make comprehensive coffee beans or sold cheaply to instant coffee factories to make three-in-one coffee and so on. Miscellaneous bitterness, muddy taste, salty taste and sour taste are the total taste of defective beans, which is difficult to swallow. A cup of coffee with a black bean or sour bean is enough to destroy a good cup of coffee. Only defective beans can meet the standards of Clean cup, and the "regional flavor" of fine coffee can be revealed. Dirty defective beans are the biggest killer of boutique coffee.

The requirements of SCAA for fine coffee are as follows: 1. There are no Class I defects in 350 g raw bean samples; 2. Deduction points of no more than 5 II defects in 350 g raw bean samples.

3. There should not be any "quaker" in 100g coffee cooked beans.

4. The color range of raw coffee beans is pale yellow (light yellow), yellow-green (yellow green), greenish (partial green), green (green), bluish-green (bluish green) blue-green (blue green).

Before selecting defective beans, raw beans need to be screened in order to make the beans uniform in size. You can use three different sizes of special custom screen, or you can use the metal screen sold in general horticultural shops, but pay attention to the size. The purpose of sieving is to separate the size of beans and remove impurities.