G.H. Mumm Grand Cordon Demi-sec is a product of a centuries old champagne-making tradition. Demi-Sec reflected the tastes of 19th-century consumers who enjoyed very sweet wine, updated for today’s tastes, Mumm Demi-Sec is the House’s gourmet signature champagne: a Cuvée that perpetuates the fine tradition of dessert champagnes.The first pages of the House of G.H.MUMM fabled winemaking history were written long before 1827, its official founding date.