Mention of Strasbourg is apt to raise “brexistential” heckles these days; but among wine bibbers, whatever their view of the European Union, it is the centre of one of the world’s most underappreciated and France’s least understood wine regions.

At the easternmost outer limits of France, in a valley that stretches north to south along the Rhine, separating France and Germany, Alsace has been passed back and forth between the two countries for centuries.