In the fall, it is crush time. The grapes are harvested. Some vineyards use mechanical harvesting techniques, but most hire workers to pick the grapes by hand. The grapes are then brought to the winery. Many wineries are located on or near the vineyards. If the wineries are far away, the grapes are shipped in refrigerated trucks.
Once the grapes reach the winery, they get crushed. Inside the crusher, there is a perforated, rotating drum. The holes in the drum allow the juice and the skins of the grapes to pass through, but keep the stems inside the drum. The crushed grapes and juice are called must.
What happens next depends on the type of grape. Red-grape must is sent directly to the fermentation tanks. White-grape must is sent first to a wine press, where the juice is separated from the skins, because white wines are fermented from skinless grapes.
The wine press consists of a stainless steel cylinder with an inflatable rubber bladder inside. The must is poured inside the cylinder and the bladder is inflated with air. The bladder squeezes the skins against the side of the cylinder and forces the juices out. The juices are collected and sent to the fermentation tanks. At some wineries, the skins are recycled to local nurseries for fertilizer.