Matusalem Gran Reserva 15 years 70cl is a well-known name in rum from the Dominican Republic. This rum matures via a solera system resulting in consistent quality. In a solera system, the Maestros Roneros (Rum Masters) use rows of barrels that are stacked with the oldest distillates at the bottom and the youngest at the top and linked together. When content is filled from the barrels, it is replenished from the rows above. This helps create a rum of consistent quality.