There are, however, other categories of Cava that require longer aging on the lees: Cava de Guarda Reserva Superior benefits from 18 months on the lees, Cava de Guarda Superior Gran Reserva starts at 30 months, and estate-bottled expressions, classified as Cava de Guarda Superior de Paraje Calificado, cannot be aged for any less than three full years on the lees.. No matter which classification it ultimately receives, each bottle will eventually be individually disgorged—that is, using the pent-up pressure to shoot out the plug of spent yeast—before being topped up and sealed with the more familiar cork and cage that the majority of them leave the winery with..}