South West France
What is the key grape variety in Côtes de Gascogne?
The key grape variety in Côtes de Gascogne is Ugni Blanc. This variety is also widely used in the production of Cognac and Armagnac in France.
Which one of these cannot be a sweet wine?
Madiran cannot be a sweet wine. Madiran is a red wine appellation in the Gascony region of South West France, and the wines are typically made from Tannat grapes. These wines are known for their strong tannin structure and deep color, not for sweetness.
On the other hand, Sauternes, Jurançon, and Monbazillac are all appellations known for their sweet white wines.