Only a small proportion of grapes grown in the Douro Valley are permitted to be made into Port - with the result that the majority of grapes are used to produce light wine. The principle vine varieties are: Tinta Roriz, Touriga Nacional, Tinta Nacional and Tinta Barroca. There have also been some plantings of French varieties: Cabernet Sauvignon, Sauvignon Blanc and Gewurtztraminer.