The newly distilled spirit is filled into oak casks and transferred
to warehouses to mature, thus softening and enhancing the flavour.
During this process, as much as 2% of the spirit in the casks
evaporates each year: this is known as the angels' share.
To be called Scotch Whisky, spirit must age in oak casks
in Scotland for a minimum of three years, however, Scotch Whisky is often matured for longer.