Vintage port is made entirely from the grapes of a declared vintage year. While it is by far the most renowned type of port, from a volume and revenue standpoint, vintage port accounts for only about two percent of overall port production. Not every year is declared a vintage in the Douro. The decision on whether to declare a vintage is made early in the second year following the harvest. The decision to declare a vintage is made by each individual port house often referred to as a "shipper".