Most whisky lovers drink their spirit with water and they do it for a reason. Adding water to the drink makes the flavours more distinct.
In recent years there has been scientific evidence that the addition of water to the alcohol causes the flavour molecules to move to the top of the drink, delivering a more pronounced taste to the drinker.
Whisky is produced by distilling fermented grains. At first it has an alcohol strength of around 70% that falls to some 55-65% in the process of maturation. The spirit is further diluted with water to around 40% before it gets into the bottle.
Researchers from Sweden’s Linnaeus University, for instance, have looked into guaiacol, one of the organic compounds in whiskies that give them taste nuances. Guaiacol, in particular, gives the smoky flavour that is more typical to Scottish whiskies and is created by smoking malted barley on peat fire. The findings show that guaiacol is mainly found towards the surface of a glass of whiskey with up to 45% ethanol. At larger concentrations, guaiacol is driven by the ethanol molecules down to the bulk.
By adding water to their whisky, drinkers are looking to create a better taste experience and how much will be added is up to the individual person.
Slighter or no dilution is recommended for very old whiskies, where water can damage their flavour balances.