During the ageing process, at least 2% of the whisky in each barrel evaporates through the oak. The distilleries refer to this portion as the Angels’ Share. Well, we’ve always known that whisky is a heavenly drink!

The exact amount of whisky lost depends on factors such as temperature and the quality of the cask.

Although 2% may sound like a small amount, at around 50 litres lost per barrel over a ten year maturation period (multiplied by thousands of barrels) it can add up to many hundreds of thousands of litres (and surely some very tipsy angels!). The longer the whisky sits in the barrel, the more is lost by the time bottling finally occurs. A twenty year old whisky, for example, can lose up to 40% of its volume to evaporation.

As you can imagine, the angels’ share represents substantial lost income for the distillers, to the tune of about £1 million per year! As a result, the whisky companies have been experimenting with ways to prevent evaporation without changing the taste of the whisky. Their findings so far? Cling film! Diageo (who own distilleries such as Talisker, Glenkinchie and Lagavulin) have apparently found that wrapping this plastic around the barrels seems to solve the problem, although they are continuing their tests before committing to this.

If they succeed and this becomes standard practice, I predict some very unhappy angels. I, for one, was hoping to continue imbibing once I had transitioned to the non-physical (a good few years hence, but still, that was the plan… assuming I passed the qualification tests for angels, that is). Now, how do I survive the spirit world without, um, my favourite spirit?!

But will Diageo succeed? Opinions are divided on the matter. After all, whisky is matured in wooden casks instead of plastic ones for good reasons – the wood removes unpleasant compounds (like sulphur) from the whisky, it adds flavour to the whisky, and its porous nature allows the whisky to interact with the atmosphere which further develops and deepens its flavour. It seems that evaporation is both essential to the making of whisky and one of its most vexing production issues.

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