Wine is made through the fermentation of grapes or other types of fruit; around 99.9 percent of the world's wine is made from grapes. The process involves harvesting the grapes, crushing them, fermenting them, allowing the wine to age and then bottling it.
In the vineyard, grapes are harvested either by hand or by machine depending on the vineyard's preferred method; both red and white grape varieties are used. Grapes may be harvested at night to capture them at their most stable sugar levels, but they are sometimes picked during the day, too. Harvesters collect the grapes in lugs or bins, and then the stems are removed either by hand or by using a destemming machine. Next, the grapes are taken to be crushed. Some vineyards still crush the grapes by walking on them while others are more modernized and use machinery for crushing them.
When making white wine, white grapes are crushed and then transferred into a press where all of the juice is extracted while leaving the skins of the grapes behind. The juice is routed to holding tanks where any sediment settles on the bottom. After a time, sediment is filtered out and fermentation is allowed to begin.
For red wine, red grapes are crushed lightly, but their skins are also transferred into the vat for fermentation. The skins actually give red wines their color. Without them, all wine would be white.