It is sad when something you have always believed in turns out to be false. I suppose I am not the only one having learned early on that the fog that causes noble rot in Sauternes occurs when cold water from the small river Ciron meets the warmer waters of the Garonne.
Now I learn that this is probably not the reason for the noble rot. Instead the truth is that some parts of the Graves region (where Sauternes is located) has such large water saturation that the moisture from the soil releases steam and thereby creates an ideal environment for noble rot.
This was revealed during the recent mapping of the soil in the Sauternes appellation. The purpose of this mapping is to help producers in choosing for instance the right rootstock when they plant new vines. The soil in the appellation proved to be very varied but with a high concentration of sand soils.
Read more about the mapping here www.lavigne-mag.fr
This post is also available in: Swedish