Depending on who you speak to, the cask that you put your whisky into to mature can contribute anything from 50 to more than 70 per cent of its final flavour. Whatever figure you land on, it plays a crucial role. One person who knows more about the impact of various forms of oak on whisky – and especially from sherry influenced casks – is Stuart MacPherson, until very recently Macallan’s Master of Wood. Stuart has now retired from the role, but Whisky Talk caught up with him to find out all about his life’s work in the world of wood – which goes all the way back to his schooldays in the late 1970s.