The Rhône Valley in France is overwhelmingly devoted to red wine production.
While the Rhône River is dotted with vineyards from its headwaters in Switzerland to its mouth on the French Mediterranean coast, the Rhône Valley properly refers to two clusters of appellations along the banks of the river in Southern France. The Northern Rhône, or Rhône septentrionale, occupies a narrow band of vineyards hugging the river just south of Beaujolais, from Vienne to Valence. The vineyards of the Southern Rhône, or Rhône méridionale, funnel outward south of Montélimar toward Avignon, near the river’s Mediterranean basin. While these two separate stretches are often considered collectively, the Northern and Southern Rhône are climatically and viticulturally distinct.
The Rhône Valley and its environs boast a long history of enological importance. The introduction of winemaking in France can be traced to the Greeks, who established vine cultivation at their Massalia settlement—modern-day Marseilles—in approximately 600 BCE. At the height of Greek trade, some 10 million liters of wine in amphorae were shipped through Massalia into the heart of Gaul via the Rhône River. The Romans continued this trend with their arrival in the Southern Rhône in 125 BCE, and viticulture spread to the Northern Rhône by the first century CE. The Northern Rhône’s picturesque, hallmark terraces were first constructed by Roman workers. Vienne evolved as an important Roman provincial capital, and the Viennese vinum picatum, or "pitched wine," was exported to Rome itself. Whether vinum picatum was simply a reference to the wine’s character resulting from its mode of transport
Question regarding grape varietals in the Rhone Valley. The Compendium entry for Cotes du Rhone AOP, as well as the AOP document itself list 21 permissible varietals, which is the number that most sources seem to concur with. Worth noting they list Grenache Blanc, Gris, and Noir as separate varietals.
According to the French Wine Society, "Within the Southern Rhone Valley, 27 grape varieties are grown... ...24 are permitted in Les Cotes du Rhone... ...the Cotes du Rhone regional AOP permits 21 of the 24... ...A total of 31 grape varieties are planted throughout the entire Rhone Valley"
By implication, there are another 10 varietals to account for, 3 of which are permitted in Les Cotes du Rhone but not under the Cotes du Rhone AOP, and additional 3 grown in the south outside of Les Cotes du Rhone, and then another 4 grown exclusively in the north. Is this in fact the case, and if so what are the varietals that are grown in the Rhone but outside of the Cotes du Rhone AOP?