The "stalk" is the stem or stalk of the grape, which containstannins , astringency and bitterness. It is also called the stalk. In the winemaking process, it is often the first thing to be removed, and the process of removing it is called destemming .
However, some producers choose not to remove the stems, but to place the whole bunch of grapes in the tank together with the grapes for alcoholic fermentation. This type of fermentation is called "whole bunch fermentation", and the resulting wine contains the complex elements of the stems.
For more information about the grape growing process, please see this website.
▶ Yamanashi Prefectural Agricultural Cooperative Association | Grape cultivation management
