to 15% Marsanne and Roussanne; whites of only Marsanne and Roussanne. Hermitage AOC - reds of Syrah and up to 15% Marsanne and Roussanne; whites of only Marsanne and Roussanne. Cornas AOC - reds of Syrah only. Saint-Péray AOC - sparkling and still whites of only Marsanne and Roussanne. Northern Rhône reds are often identified by their signature aromas of green olive and smoky bacon. Southern Rhône The southern Rhône sub-region has a more Mediterranean climate with milder winters and hot summers. Drought can be a problem in the area, but limited irrigation is permitted. The differing terroirs, together with the rugged landscape which partly protects the valleys from the Mistral, produce microclimates which give rise to a wide diversity of wines. A feature of the cultivation of the region is the use of large pebbles around the bases of the vines to absorb the heat of the sun during the day to keep the vines warm at night when, due to the cloudless skies, there is often a significant drop in temperature. The southern Rhône's most famous red wine is Châteauneuf-du-Pape, a blend containing up to 19 varieties of wine grapes (ten red and nine white) as permitted by the Châteauneuf-du-Pape AOC rules. Other nearby AOC regions including Côtes du Vivarais AOC, Grignan-Les Adhemar AOC, Lirac AOC, Tavel AOC, Vacqueyras AOC, and Ventoux AOC may contain even more varieties in the blend. Gigondas AOC, on the other hand, is predominantly made from Grenache noir has a more restricted set of permitted grapes. Depending on the specific AOC rules, grapes blended into southern Rhône reds may include Grenache, Syrah, Mourvèdre, Carignan and Cinsault. Similar wine blends globally are known as GSM, after the first three varietals. The reds from the left bank are full bodied, rich in tannins while young, and are characterized by their aromas of prune, undergrowth, chocolate and ripe black fruit. The right bank reds are slightly lighter and fruitier. Southern Rhône appellations: Côtes du Vivarais AOC Côtes du Rhône AOC Côtes-du-Rhône Villages AOC Côtes du Rhône Villages (named villages) Châteauneuf-du-Pape AOC Grignan-Les Adhemar AOC Vacqueyras AOC Rasteau AOC Cairanne AOC (Accepted in February 2016 - Official decree pending) Gigondas AOC Vinsobres AOC Lirac AOC Beaumes de Venise AOC Muscat de Beaumes de Venise AOC Tavel AOC White wines from the southern Rhône sub-region, such as in Châteauneuf-du-Pape whites, are also typically blends of several wine grapes.