This is a regional specialty of the Jura, taking partially fermenting grape must and introducing a Marc du Jura, or grape eau de vie, which preserves some sugar and brings the alc. up to about 18%. It's a similar approach...

From Vins de Lieu website: A blend of Enfariné, Geuche, Portugais bleu, Béclan, and Mézy. This red comes from the co-planted plot of ancient Jura varieties close to the Monnier home. The grapes are hand harvested, de-stemmed, then put into...