1. According to the different colors of grapes, grape varieties can be divided into white varieties (white skin and white meat), red varieties (red skin and white meat) and dyed varieties (red skin and red meat). White wine can be brewed from white varieties, red wine can only be brewed from dyed varieties, and various wines with different colors from white to dark red can be brewed from red varieties.
2. White wine is fermented with white grape juice, red wine is fermented with grape juice (liquid part) and grape skin dregs (solid part). The color of red wine depends on the strength of liquid part to solid part. The stronger the impregnation, the darker the color.
3. The solid part brings not only pigments, but also tannins, which are phenolic substances like pigments. The darker the color of wine, the higher the content of phenolic substances composed of pigments and tannins.
Therefore, the main difference between red wine and white wine lies in the content and type of phenolic substances between them.