First and Second Fill American Oak and ex-Sherry casks.
"Over the course of 18 years our Master Distiller, Alan Winchester, takes this expression through a combination of cask types, including both first and second-fill American oak (for tropical fruitiness) and ex-sherry oak (for spicy complexity). The result of this deft navigation of the distilling arts is a gorgeous single malt that is complex, yet elegant and balanced. The 18 Year Old has won more awards than any other expression; every bottle is a true example of the quality and taste of The Glenlivet. Any bottle deserves pride of place in your cabinet… perhaps to be held back for a fitting occasion? It is, after all, crafted to impress."