Fonseca belongs to the first league of Port Vintage wine producing houses. Few Port Wine Producers have maintained this consistency of quality and style in every Vintage.

In some years, when there is no classic Port Fonseca Vintage wine, a Vintage Guimaraens can be produced instead. Even so, Port Guimaraens Vintage wines share the origins, heritage and complex fruity style of Fonseca's classic vintages and come from grapes from the same three farms.