The method by which the young wines described above are brought through a course of training, it may be said, to convert them into the real sherries is a most interesting chapter in the history of sherry. Almost all wines with which we are commonly acquainted, such as the red and white wines of commerce in all countries, are matured in casks by the refining and racking processes which depend upon natural sedimentation.

The process in ordinary wines lasts from two to five years, at which period the wines are said to be ripe and ready for bottling. During this time the shrinkage in the casks is made good by the addition of other wines of the same kind, so that the casks are kept practically filled. From 4 to 12 rackings are sometimes practised in the complete refining and racking of ordinary wines.

In the process of developing a sherry wine an entirely different method is pursued. This process is known in Spain as the Solera System, and is a method peculiar to Jerez and its neighboring districts of San Lucar and Montilla.