Coffee beans are not beans.

Coffee beans refer to the fruit of the plant used to make coffee. Broadly speaking, there are two types of coffee beans in the world, Arabica beans and Robusta beans. The coffee fruit is composed of two oval-shaped seeds facing each other. The side that connects to each other is a flat joint, which is called a flat bean. But there are also those consisting of a round seed, called round beans, which taste no different.

Undesirable types:

Fermented beans are fermented coffee beans dropped in the soil before harvesting. The moldy smell will have a great impact on the delicious taste of coffee.

Dead beans, also known as immature beans, may be affected by climate factors and are not fully developed. After roasting, spots will appear, giving the coffee a green and astringent taste.

Black beans are fermented beans, coffee beans that have become rancid and blackened. Because they are black, they can be distinguished from normal coffee beans at a glance.

Both beans Coffee beans that have been infested by insects. Incomplete beans may be caused by jamming during operation or careless handling during transportation, resulting in incomplete coffee beans. It will cause fried spots when roasted, and will produce bitter and astringent taste.

Other beans with thin skins remaining, beans with stunted growth, beans with a musty smell due to incomplete drying, and beans with only shells (shell beans).

Reference for the above content: Baidu Encyclopedia-Coffee Beans