G.H. Mumm has nearly 218 hectares of vineyards rated at 98% on the Champagne quality scale.These are mainly sited in the eight most renowned Grands Crus in Champagne: Ay, Bouzy, Ambonnay, Verzy, Verzenay, Avize, Cramant and Mailly-Champagne. These holdings cover 25% of G.H. Mumm's production needs. The remaining 75% comes from independent growers with whom the company has developed strong ties.This combination of its own vineyards and external supply enables the House of G.H. Mumm to maintain a consistent style and continue its philosophy of close scrutiny over grape quality.