Tawny Ports are wines made from red grapes that are aged in wooden barrels using the Solera process, exposing them to gradual oxidation and evaporation. As a result, they gradually mellow to a golden-brown colour. The exposure to wood imparts "nutty" flavours to the wine. When a Port is described as Tawny, without an indication of age, it is a basic blend of wood aged port that has spent at least seven years in barrels. Above this are Tawny with an indication of age which represent a blend of several vintages, with the average years "in wood" stated on the label.