What grape variety is chiefly used in the key AC wines from the Nantais?

The grape variety chiefly used in the key AOC wines from the Nantais is Melon Blanc, more commonly known as Melon de Bourgogne. This grape is primarily grown in the Muscadet region, which is located in the Nantais area of the Loire Valley in France. Muscadet is well-known for its crisp, refreshing white wines that are often enjoyed with seafood. Melon Blanc is particularly suited to the cool climate and terroir of this region, producing wines that are characterized by their high acidity and mineral qualities.

The importance of Melon Blanc in the Nantais cannot be overstated, as it forms the basis of the Muscadet wines that define the region. The typical vinification process involves fermentation on fine lees, a technique known as sur lie aging, which enhances the texture and complexity of the wine.

The other grape varieties mentioned do not play a significant role in the AOC wines from the Nantais. Glera is predominantly associated with Prosecco production in Italy, Sauvignon Blanc is more characteristic of regions like Sancerre and Pouilly-Fumé in the Loire and is not the primary grape in Muscadet, and Riesling is typically found in regions like Germany and Alsace rather than in the Nantes area