Coffee knowledge: ten kinds of defective beans in coffee

One of the most important factors affecting the quality of coffee is defective beans. The number of defective beans also affects the grade of coffee. For example, the coffee evaluation method used in Brazil is the "deduction method", which is graded according to the number of defective beans in 300 grams of staple beans per gram.

For example, coffee is hand-selected, so successful hand-selection is also necessary to have a comprehensive understanding of the types of defective beans. From this, we can see how important coffee defective beans are to coffee, but defective beans are only a general term, so how many kinds of defective beans are there? Please take a look at this article: how many kinds of coffee do you know?

First, shell beans

The endocarp of coffee covers the inside of the pulp of coffee beans and remains on the coffee beans treated by washing. The poor heat permeability when roasting and sometimes burning is the reason for the astringent taste of coffee.

Others include broken beans, red peeled beans (beans formed by rain in the process of natural drying, which taste dull and monotonous), stunted beans (small granulated beans that stop growing due to lack of nutrients, strong flavor), and sometimes mixed with corn kernels or pepper kernels.

2. Stone

The beans harvested are easy to be mixed with stone or sawdust because of the natural drying method.

Third, moldy beans

Because the drying is not complete, or in the transportation, storage process is too wet, and the growth of cyan, white mold, sometimes make beans stick together, if you do not remove these moldy beans, it will produce moldy smell.

4. Fermented beans

It is mainly divided into two categories: one is that the coffee is soaked in the fermentation tank for too long when the coffee is washed, and it is formed by the water pollution of the washed coffee beans; the other is the relationship of stacking in the warehouse, so bacteria are attached, and the surface of the beans becomes mottled. The appearance of fermented beans is not easy to distinguish, so special attention should be paid to hand selection. Fermented beans will smell rotten if mixed with coffee.

5. Dead beans

Beans with abnormal results. The color is not easy to change because of baking, so it is easy to distinguish. The taste is insipid, as harmful as silver skin, and will become a source of peculiar smell.

6. Unripe beans

The beans picked before they are ripe have a fishy and disgusting taste. Keeping coffee beans for several years is a countermeasure to deal with these immature beans.

Shell beans

Caused by poor dryness or abnormal hybridization; the bean breaks from the central line and the inside is turned out like a shell. Shell beans can cause uneven baking and are easy to catch fire during deep baking.

8. Worm-eaten beans

Moths invade and lay eggs when the coffee fruit ripens and turns red, and the larvae eat the coffee fruit and grow, leaving traces of moth on the surface of the beans. Moth-eaten beans can cause cloudy coffee juice and sometimes produce a strange smell.

9. Black beans

Beans that ripen and fall off early and ferment and blacken due to long-term contact with the ground. It can be easily selected by hand. Coffee mixed with black beans will smell rotten and turbid.

10. Cocoa

The reason for its formation is that the pulp remains and the pulp is not fully shelled by natural drying. With iodine, soil and other flavor, there will be a stink similar to ammonia. "Coco" means "dung" in Portuguese.