There has been much debate over the roots of the Primitivo grape. Recent DNA fingerprinting has proven that California's Zinfandel is the same as southern Italy's Primitivo. The genetic findings delve even deeper: Studies by the grape geneticist Carole Meredith, a professor at the University of California (Davis), have confirmed that Primitivo and Zinfandel are identical to the Croatian variety, Crljenak Kasteljanski. In southern Italy's Puglia, Primitivo is the third most planted grape and is the sole varietal used in the region's only DOCG wine, Primitivo di Manduria Dolce Naturale. To create this decidedly sweet wine, Primitivo grapes often undergo the apassimento process, a method of rying the grapes to concentrate their sugars. To learn more about Primitivo-based wines, be sure to look through our Primitivo Wine Reviews.