Paul John (whisky) evaporation during aging, known as the angels' share, is also higher in India, at 10–12% per year, than in Scotland, where the annual evaporative loss is about 2%. This leaves a hogshead with only 150 bottles left in it, after three years, compared to around 350 in a Scotland. Michael John describes it this way, "Whisky matured at these temperatures simply cannot be aged for the kind of time expected with Scotch, even trying to mature our whisky for just 10 years would leave barely a bottle of liquid in the barrel. Fortunately, the heat actually speeds up the maturation
Whisky identified 40 different phenolic compounds. The coumarin scopoletin is present in whisky, with the highest level reported in Bourbon whiskey. In an experiment, whiskey aged 3 years in orbit on the International Space Station tasted and measured significantly different from similar test subjects in gravity on Earth. Particularly, wood extractives were more present in the space samples. Depending on the local regulations, additional flavourings and colouring compounds may be added to the whisky. Canadian whisky may contain caramel and flavouring in addition to the distilled mash spirits. Scotch whisky may contain added (E150A) caramel colouring, but no other additives. The