Racking

racking, the winemaking operation of removing clear wine from the settled sediment or lees in the bottom of a container. The verb to rack has been used thus at least since the 14th century.

Racking is usually achieved by pumping or siphoning the wine away from the sediment into an empty container but special large racking tanks are used by some large wineries (and breweries). They are equipped with drain lines, the lower ends of which can be adjusted to just clear the sediment layer and permit more rapid and more complete wine removal from the solids.