Champagne is a dénomination of origin. It is a sparkling wine produced only in France in the delimited area of Champagne according to strict regulations. As such several mentions are compulsory on the label among which the name CHAMPAGNE
「This is not written on the label so Soumei is not Champagne.」
Attached is a document that should answer your questions about Champagne.
Brigitte Batonnet
brigitte.batonnet@civc.fr
Comité interprofessionnel du vin de Champagne
(+33)0326511930
www.champagne.com