Botran Solera 18 Rum is a rum aged for an average of 18 years in a solera ageing system. Guatemalan Rum has its own Protected Designation of Origin (PDO) which is both a designation of quality and geographical limitation. It means than certain processes, fermentation, distillation, ageing in the solera system etc. have to be adhered to. Guatemala has an ideal climate for growing sugar cane and Botran Rums are made from virgin sugar cane syrup. Botran Rums are aged in a Solera system, this is a system of fractional aging developed in Jerez, Spain for Sherry production. To simplify, if one imagines 3 layers of barrels with the oldest rum in the bottom and the newest rum at the top. The oldest rum is drawn off at the bottom and is continually replaced with new rum from the barrels above, which is in turn topped up from the top layer above that . The top layer of barrels is topped up with youngest rums. This is a very simplified idea of the Botran Solera process. There are different off-shoots of the solera and re-blending of the rum along the way. Because Rum is continually mixed in the solera, Botran cannot put the age of the rum on their labels. The labels state that the rums are Botran Solera 12 Rum or Botran Solera 18 Rum. This is a rough average of the age of the rums in these bottlings. There will be rums older and younger than 12 or 18 year old in the Solera 12 or Solera 18 respectively. The oak barrels used for ageing Botran Solera 12 Rum in this solera system is a mix of four different types of barrel – fresh and charred ex-Bourbon Whiskey Cask, ex-Sherry casks and ex-Port casks – I think I am right in saying they are the only Rum producer who use four different cask types. This is also known as Botran Solera 1983.