Why water makes whisky better
Seasoned whisky drinkers have always done it, but now there’s a scientific explanation to back up why it’s better for your tipple to have a drop of water.
New research from Sweden’s Linnaeus University explained why slightly diluted whisky had an enhanced flavour, as opposed to drinking it neat.
The taste of whisky was primarily associated with something called guaiacol, known to give a smoky flavour, so the researchers put the molecule’s relationship with water to the test.
Using computer-based simulations of water and ethanol mixtures with guaiacol, the researchers found the molecule preferred to linger in alcohol. That meant that adding more water might help to draw it from the whisky, in the form of gas.
The research said guaiacol stayed in the alcohol with concentrations of 45 per cent or more, so lowering below that point helped draw it out. Whisky was typically diluted to 40 per cent by distillers, initially placed in the barrel at about 70 per cent before three years of ageing. Alcohol typically evaporated to make the alcohol 55 to 65 per cent and was further diluted by the whisky makers.
Victoria University organic chemistry senior lecturer Rob Keyzers said flavour and taste were two different things, and the nose had a role to play.
‘‘That’s where we detect flavour,’’ he said.
The tongue detected tastes, such as sweet or salty, but the flavours that differ between foods was detected ‘‘retro-nasally’’, he said.
That was why wine-tasters put their noses into glasses and are able to recognise certain types of wines, he said. ‘‘Adding reasonably small amounts of water to whisky alters, in this case, guaiacol.’’
‘‘The ethanol helps it stay dissolved, and it’s happy there. By adding the water you make it less happy to be dissolved and it wants to release. It’s all about changing the distribution really, of how much how much is dissolved and how much is travelling up the back of your nose.’’
Adding water also had a dilution effect, Keyzers said. ‘‘There’s a balancing act around how much you can force into the gas stage and how much you get per 100ml or 10ml.’’
He said this research was a ‘‘really good place to kick off experimental research’’, taking into consideration people’s tastes and preferences.
Adding ice was a different story all together, he said. Ice could suppress the ‘‘hot’’ feeling in the mouth and some of the taste, but could melt and add to the flavour.
‘‘You couldn’t put it down to one thing, and ice will have a different effect to water. There’s all sorts of subtleties there.’’