What geographical feature protects the Alsace AOC, making it suitable for Riesling production?

The Vosges mountains play a significant role in protecting the Alsace AOC from the adverse effects of weather patterns, making it particularly suitable for the production of Riesling. This mountain range acts as a barrier against the moist winds coming from the west, typically from the Atlantic Ocean. As a result, Alsace benefits from a relatively dry climate, which is essential for grape growing, especially for varieties like Riesling that thrive in such conditions.

In the case of Riesling, the grape's aromatic complexity and acidity are best developed in a climate that experiences sufficient sunshine yet remains dry during the growing season. The Vosges mountains create this microclimate by blocking precipitation, contributing to the region's unique terroir. The combination of well-draining soils and the protection from excessive rainfall allows Riesling grapes to ripen fully, resulting in wines that are known for their expressive characteristics and high quality.