Where can you tell whether coffee is good or bad by coffee beans?

How to tell whether coffee is good or bad? Like taste? Color? Solubility?

There are only two ways to identify coffee:

(1) pre-brewing identification?

High-quality instant coffee-brown to dark brown due to different varieties and processes; irregular particles about 2 mm in size, mixed with some fine powder; unique aroma of coffee due to Maillard reaction during stir-frying. ?

Inferior instant coffee-dark in color, some iron black; caking or agglomeration in tissue due to moisture or other reasons; coffee roasting flavor is weak or can not be smelled at all, replaced by a strong scorched flavor.

(2) Identification after brewing?

Good quality instant coffee-completely dissolved, free of dregs and suspended matter; the soup juice is brown and bright; it has a strong coffee aroma; it has a pleasant bitter and sour taste after adding sugar. Inferior instant coffee-after dissolving, there is sediment at the bottom of the cup, and the soup is dark and brown-black (at the same concentration); the aroma is light, but the scorched taste is strong; after adding sugar, the bitter and sour taste is strong, especially after hard aftertaste.