Rum

Rum is a sugarcane spirit produced all over the world, however its best-recognised brands mostly originate in South America and the Caribbean. It can be distilled from a wash fermented from either fresh cane juice, syrup or molasses, a sweet treacle substance and by-product of sugar refining. Rum distilled from each has different qualities, and casks used to age both have been used in whisky maturation.

Rum is often sold unaged but when it is cask matured, this ordinarily takes place in ex-bourbon casks meaning most rum wood used to age whisky will at the very least be onto its third filling. This is in part due to cost, bourbon barrels are cheaper than new oak and many rum distillers are in close proximity to the US. Climate however is also key, with highly active new oak casks less suited to the rapid maturation often brought on by the tropical conditions of most distilleries. Of course, ex-rum casks can come in many forms, with large 500 litre machine puncheons also historically common.

Early pioneers in the use of rum casks to age whisky were Springbank distillery, who released a legendary single malt aged fully in a rum butt in 1991. The practice did not pick up steam until the 21st century however, notably kick-started by the infamously titled Havana Reserve from Glenfiddich, launched in 2002. Rum casks are now increasingly experimented with by single malt producers across the globe and have even infiltrated the American whiskey market as it slowly normalises the idea of cask-finishing its bourbon.