In the Octave series, Duncan Taylor experiments with the influence of barrel size on maturation. Octave barrels are only a fraction of the size of common barrel types. This means the whisky has more contact with the surface of the barrel and matures more intensively. Both Single Grain whiskys have been distilled in 2009 and bottled in 2021. The Girvan aged for 12 years in oak cask #2129943 and a further 3 months in a octave cask before being exclusively bottled for Soul of Whisky. Bottle no 35 of only 88. The Invergordon aged for 12 years in oak cask #5229895 and a further 5 months in a octave cask, bottled in 2021 exclusively for Absolutely Nuts Spirits at cask strength. Bottle no. 91 of only 94.