Definition - What does Racking mean?
Racking is the process by which wine is removed by pumping it from one holding tank to another in order to separate it from its lees. Depending on the wine and the style of wine a winemaker wished to achieve, racking may be performed many times before the final product is bottled. It is done more frequently with red wines.
WineFrog explains Racking
Racking a wine is done by pumping wine from its holding or aging vessel into another vat so that it can be removed from the solid particulates, which settle to the bottom. These solids are made up of dead yeast cells, grape skins and much more.
Once a wine has finished fermentation, it is moved to a holding tank or barrels where it can be aged. As the wine settles, solids which are normally suspended will precipitate out. These solids are called lees.
In the case of red wine, the lees can make the wine bitter. Therefore, red wine is typically racked many times before it is fined and finished. In the case of white wines, they are rarely racked, because these solids add positive characteristics to the wine. White wine is usually only racked after fining and before bottling.