MrTattieHeid wrote:This is done for Balvenie 15 (Single Barrel), also. I assumed it was a cask strength at first, but realized it was pretty unlikely that every barrel would be at 47.8% (which is rather low for a 15yo cs, anyway). Either they think that's a pretty good strength (and it is, but why 47.8 exactly?), or it's more economical for them to water the whisky than to change the percentage listed on the tube.
It might be slightly more economical, but I think it would be a better commercial argument to label the bottle "Cask Strength". The main reason is for taxation. In many countries, spirits are taxed based on the content of alcohol. If the volume of alcool would vary between batches, the companies would need to issue each time new export forms and so forth. The administrative would to be too high for high volume products.