Bia blanc Bia blanc Bia blanc is a white French wine grape variety that is no longer commercially cultivated for wine production with only a few plantings existing worldwide in viticultural archives and experimental vineyards. The exact origins of Bia blanc are not yet known though ampelographers have noted that the grapevine shares some morphological similarities to the red Isère grape Peloursin, one of the parent varieties to Petite Sirah (Durif). In the 20th century, ampelographers Louis Levadoux and (decades later) Linda Bisson categorized Bia blanc as a member of the Pelorsien eco-geogroup along with Durif, Béclan, Dureza, Exbrayat, Jacquère, Joubertin, Mondeuse
Peloursin California vineyards that thought they were planted with Durif/Petite Sirah were found to be field blends that contain some plantings of Peloursin. In addition to being a parent of Durif, Peloursin was also crossed with Persan to create Joubertin. DNA testing also suggest a relationship between Peloursin and Bia blanc which share some morphological similarities but the exact nature of that relationship is not yet known. Plantings of Peloursin are often confused with its offspring Durif and this was particularly the case in California where many plantings of Petite Sirah/Durif were discovered to actually be Peloursin. In the Jura region,