Few Words About Water & Ice in Whisky

There are many things whisky lovers love to debate, but the particular question of adding water or ice to whisky has been known to ignite raging (Twitter) infernos. So herewith, a look at the history and science of the effect of temperature and dilution on our favorite libation.

The history of whisky is replete with wonderful myths and legends – the origin of the phrase “on the rocks,” meaning “with ice,” is likely one of those. Popular tales have it that Ye Olde Scotsmen would place cold river stones into their rough usquebaugh to tame some of its fire. But the OED doesn’t give us an oldest known usage, and several etymology websites date the phrase to 1946 without citing a source. Regardless, every whisky drinker has a specific expectation if they order a dram using that phrase.

The idea supporting including ice is that it will make the whisky more enjoyable to drink, while the contention is that dilution “dilutes” the flavor.

To ice, or not to ice? That is a whisky drinker’s dilemma.

So which is right?

Well – purely anecdotally, mind you – I’ve heard that in certain parts of the U.S. South illicit liquor may be found in little mason jars in some folks’ freezers. It is apparently much easier to imbibe at sub-zero temperatures, then if the little jar had been left out on the counter.

There’s actual science to back that up. The ‘heat’ of beverage alcohol comes from the ethanol molecules triggering the nerve endings that respond to heat, and those in turn send a pain signal up to the brain. The higher the concentration of alcohol, the more the burn. Secondary compounds common in whisky from the grains and the barrel act to exacerbate the effect.

But the human brain doesn’t like contradictory information, so a cold beverage which triggers the nerves in the opposite direction will actually cancel out the perception of heat in the brain. So that frozen ‘shine doesn’t seem quite so hot!

Ergo, ice = more enjoyable whiskey. But what about that dilution, I hear some people cry?

Dilution does, in fact, dilute the flavor of whisky – in certain circumstances, but not in all.

A common tradition in Scotch is to ‘open’ a whisky by adding a few drops of water. Possibly inspired by the debate (or possibly to expense some whisky), in 2017 Björn C. G. Karlsson and Ran Friedman published a molecular analysis of dilution in whisky. Long paper short:

Thus, the taste of guaiacol and similar compounds will be more pronounced when whisky is further diluted in the glass. This taste-enhancement is counteracted by the dilution of guaiacol’s concentration. Overall, there is a fine balance between diluting the whisky to taste and diluting the whisky to waste. This balance will depend on the concentration and types of taste compounds that are characteristic for each whisky. Similar considerations can be used to optimise the alcohol concentration of other spirits including gin, rum and brandy.

So a Bourbon and Branch isn’t a bad thing, to a point.

In order for the opening effect to work (and not to take the whisky to waste), there must be specific types of taste compounds present at sufficient concentrations. It would seem then that, in general, higher proof whiskies with high flavor potential are the best candidates for enhancement with water. Any whisky, but especially the high proof variety, may benefit from the heat reduction induced by coolness. Individual mileage may vary.

When manipulating dilution and temperature in whisky, “on the rocks” often offers the best of both worlds, with both a reduction in heat and an increase in flavor as long it doesn’t wash out. One option occasionally presented by bartenders is the ‘chilled and strained’ mechanism of stirring or shaking spirit over ice, then straining it and presenting it neat, preferably in a chilled glass. Another method is to use a large ice cube or sphere, with the latter having a smaller surface-to-volume ratio that will cause less dilution. The bigger the ice chunk, the better because the greater the thermal mass, the slower the melting.

If you’re playing along at home, remember that the quality of the water matters when making ice or adding it directly to whiskey. Tap water usually contains off-flavored compounds, so try using pure spring or distilled water instead.

My recommendation is to always try the Whisky neat, unless it’s a cask strength and even sometimes even with a cask strength. Then add just few drops of bottled water then make your decision whether you add more or not. Everyone is different and so are the Whiskies so you find where it’s the most enjoyable for you to get the fullest flavor and enjoyment from your Whisky. Personnel preference NEVER add ice.

Am I Adding The Wrong Water To My Whisky?

Just as The Whisky Virgin wraps his head around the debate of adding water to a dram of Scotch, he discovers a whole new dispute bubbling just below the surface: whether some types of water are of inferior quality, and can even spoil a whisky’s flavor.

Murky Waters

Do certain types of water have a negative effect on a whisky’s taste?

When I first started out on my voyage of whisky discovery I wasn’t sure what the deal was with adding water to a dram. I worried that by adding a few drops to turn down the heat I’d out myself as a total newbie. But it seems that after years of Scotch-fueled debate and some scientific studies, this is a closed case.

The verdict: it’s fine to drop a little water in your whisky if you feel like it. Turns out reaching for the water jug is just a way to fine-tune your whisky to suit your palate. I even hear tell that doing this can bring different flavors out of a whisky. Sounded good to me. But then I came across a question that changed everything.

What kind of water should you add to whisky?

Uh, the regular kind? Two parts hydrogen, one part oxygen? Comes out of the tap… from the ground? Is there really a wrong sort of water? Goddammit whisky! Every time you feel like you have understood something about you, you go and get more complicated.

So apparently, debate rages about the best water for optimum whisky slugging. Some veteran drinkers go so far as to say the chemicals and impurities in tap water will mess up the flavors in a Scotch, even if you only add a few drops. Such purists seem to think that we should be buying de-ionized or distilled water to up our dilution game. Others reckon the best is natural spring water, bottled straight from the source in Scotland, if you can get it. You’d have to be to get special water shipped to you from whisky country.

Naturally sourced: Some whisky fans will only add mineral spring water to their Scotch

It makes sense to me that regular water can carry flavors and smells that might get in the way of serious whisky sniffing. Where you live, maybe the tap water here is totally chill to drink, it also has a certain dog-in-a-swimming-pool thing going on. I’d never thought about it before, but it seemed totally possible that cutting my drams with a drop of the tap water could compromise their integrity. Had I really been ruining precious whisky with inferior H2O?

Some specialist water dealers out there seem to say so.

I just learned about a company called Uisge Source (which sounds Scottish AF) that bottles water captured from the wild, up in Scotland’s different whisky-producing regions. The idea, I guess, is to have Speyside water with Speyside whisky and so-on. Now I can tell you, having been there recently, that Islay water has its own particular honk, but do I really need to pay someone to ship it all the way from the literal Hebrides to accentuate my Islay whisky? Is that a homeopathy thing?

Another aspiring player in the whisky water game called Larkfire just dropped, a rival Scotch water in little minibar-sized cans. Their website also says I’m killing whisky with chlorine if I put tap water in it. Huge if true.

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