Winter Squash Soup with Vin Jaune

I’ve lost track of the origins of this soup, which might have been my own innovation. It uses vin jaune, the unusual, very dry white wine from the Jura region of eastern France, which has an oxidized taste from being aged, like sherry, sous-voile, “under a veil” of protective yeast. The wine’s flavors, which partly recall those of sherry, flatter the nu…