White wine can be produced from either white or red grapes. As long as the skin of the red grapes are not introduced, then the wine will appear white/yellow not red.
White wine production starts with the pressing procedure. Pressing is normally accomplished by a machine. There is a mechanism inside the mechanical pressing machine that inflates so as to gently apply pressure against the grapes so the grape skin breaks. This is a gentle procedure.
After the grapes go through the pressing process, the juice and grapes sit overnight in a refrigerated tank. This "sitting" allows the pulp/skin to settle out.
Next is the controlled fermentation process. The juice is then placed in a container of the winemakers choice. There are all types of containers to choose from. Examples include: wooden barrels, fiberglass tanks, or stainless steel tanks. It just depends on what type of white wine the winemaker wishes to produce.
When the juice is in the container, then the fermentation process begins. The temperature of this process will change the wine. (cooler fermentation = white wines)
This process of fermentation continues until either all the sugar turns to alcohol or the winemaker stops the process leaving some residual sugar in the wine. The white wine is now complete. The wine may go through a clarification process which makes white wines look so clear and bright.
If you wish to know more buy the book. It explains all this in much greater detail.