Is it related to Syrah? Is it not related to Syrah? Well, about the only thing that most experts will agree upon is that Petite Sirah is the term used for a collection of grapes found widely in California and South America, and that they are responsible for heavy and tannic wines full of currants and pepper. There has been DNA tests both proving and disproving that it is identical to the Durif varietal that is now becoming scarce in France.
For a long time Petite Sirah was responsible in California for "jug" style wines, but the combination of older vines and heavy tannins have given the Petite Sirah in the warmer regions of California a new life along with most other Rhône varietals. This is related in some part to the resurgence of Syrah. Also found throughout Argentina.