What are the types of coffee "defective beans"? How to distinguish defective beans in coffee?

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Moldy bean

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 these moldy beans are not removed, they will produce a moldy smell.

Dead bean

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.

Unripe bean

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.

Fermented bean

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.

Shell bean

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.

Moth-eaten bean

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.

Black bean

Beans that mature earlier and become black after long-term contact with the ground can be easily removed by hand-selected steps.

Coffee mixed with black beans will smell rotten and turbid.

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.

Black beans-phenolic acid, earthy taste, moldy taste, sour taste.

Sour beans-fermented, smelly beans.

Immature beans-straw, straw, stink, astringency.

Moldy beans-fermented flavor, phenolic acid, earthy taste, mildew taste.

Moth-eaten beans-earthy, sour, moldy.

Floating beans-fermented, moldy and earthy.

Shrunken beans-straw, straw.

Shell beans (shell)-scorched and mushy.

Broken beans-earthy, sour, fermented.