The agave juice is extracted into a large vat where it is fermented with the same "prisse de mousse" yeast used in the fermentation of Champagne. Throughout this delicate slow fermentation process, Siembra Azul is gently serenaded around the clock by the sounds of Vivaldi and Mozart, in a sophisticated technique known as "serenading" the tequila. The soothing rhythms and gentle vibrations is thought to have a positive effect on the living yeast cultures, and helps to produce a smooth, mellow tasting tequila.