Tony Debevc, Sr. keeping a watchful eye on the crusher-destemmer machine process.
The device shown serves two purposes; it separates the grapes from their stems and gently breaks open their skins. The grapes are tumbled from a massive bin into a large metal hopper and then they are funneled into a destemmer, which rotates to remove the stems while at the same time lets the berries fall into a separate machine where they are lightly crushed. Typically, the grapes are then transferred to containers to begin fermentation with the skins or they are moved directly into a press.
Image Courtesy of the Ohio Wine Producers Association.