Definition - What does Mechanical Crushing mean?
Crushing grapes is a process that takes place after picking and is completed before fermentation, unlike pressing, which squeezes the juice out of the must, crushing simply opens the grapes up so the juice can start to flow out. Advances in modern technology have allowed the winemaker to move from manual crushing to mechanical crushing where machines are used to crush the grapes instead of the feet or hands.
WineFrog explains Mechanical Crushing
In mechanical crushers, the grapes are removed from the stems and then added to a machine that gently breaks open the skin permitting the juice, skins and solids to run freely into the collection area. Some mechanical grape crushers also have de-stemmers as a feature that removes the stems as well as breaks open grapes. They are typically made up of steel or aluminum, prism-shaped bins that have a turning screw type mechanism that rotates on the bottom, pulling the grapes in and crushing them slowly. Crushing is done before pressing for all wines, but in white wines, the skins are removed immediately, and in reds, they are left in contact with the juice to acquire typical red flavors and characteristics. Mechanical crushing has helped winemakers maintain quality and increase sanitation as well as facilitate large scale commercial operations by offering time saving alternatives to manual crushing.