What Grapes are in Port?

Port is a style of dessert wine originally from Portugal but now made throughout the winemaking world. The wine is defined by the style in which it is made, not the grapes used. The grapes vary, depending on where the wine is made.

Portugal:
Controlled by the Instituto do Vinho do Porto, the grapes used for port in Portugal are closely controlled and are usually:
-Tinta Barroca 
-Tinta Cão
-Tempranillo
-Touriga Francesa
-Touriga Nacional

New World:
Much more flexible in their definition of Port, New World wine makers have a range of grapes they can use, depending on climate and what local grapes will best work to match the style.
-Portugese varietals
-Zinfandel
-Cabernet Sauvignon
-Petite Sirah
-Chardonnay
-Sauvignon Blanc
-Chambourcin
-Marechal Foch