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
Single malt whisky more are not uncommon. During the time it spends in the wood, a significant percentage of each cask's content will evaporate. The lost product is known as the angel's share. The selection of casks can affect the character of the final whisky. Outside of the United States, the most common practice is to reuse casks that previously contained American whiskey, as US law requires several types of distilled spirits to be aged in new oak casks. To ensure continuity of supply of used oak casks some Scottish distilling groups own oak forests in the US and rent the new barrels