Yeast is a single-cell fungus that survives by breaking down organic material. In whisky production, yeast has a much wider purpose than simply turning sugar into alcohol. Many of the flavours in the final product come from yeast – or at least they can, if the focus is removed from simply trying to produce as much alcohol as possible. At Box, we use French distilling yeast, a type that offers the distiller much more choice in how they affect the flavour of the distillate. We also let our yeast work for unusually long periods so that we can extract as much flavour as possible from the mash.