Post image for Whisky Myths Debunked #3 – The Importance of Water

Whisky Myths Debunked #3 – The Importance of Water

by Oliver Klimek on July 7, 2010

Ever so often I read about the almost mystical influence that water is supposed to have on whisky. But how big an influence can water actually have on the water of life? Let’s examine.

How Does Water Taste?

If you ask anyone on the street about the the taste of water, chances are you get a surprised look and the answer “Of nothing”. And most probably the person will doubt the seriousness of your question.

If you compare spring water samples though, you will detect differences. The mouthfeel of hard and soft water for example is noticeably different. Also there are fluctuations in taste caused by varying amounts of minerals. I am not talking about chemical additives to tap water like chlorine, by the way. Some waters can be slightly salty, some might have a bitter touch to them.

So there are noticeable differences, but to be honest, they only are very slight in most cases. Only some springs with extreme mineral content will display strong flavour notes.

What is Water Made of?

Another stupid question, I know. But it proves to be important nevertheless. Basically, regular spring water consists of H2O and the solved minerals during its journey through soil and rock. Anything else we definitely don’t want to have in our drinking water: heavy metals, pesticides, fertilizer and so on.

Drinking Water = H2O + Minerals

A Closer Look at Distillation

The main purpose of distillation is to separate the alcohol and aromatic components contained in the wash from the water. This is done by gradual heating of the liquid to slightly below 100° C, the boiling point of water. This works because fortunately the “good stuff” has evaporation temperatures below that mark. Due to the deliberate imperfection of a pot still, there still is a certain amount of water vapour finding its way through the condenser, so the process has to be repeated at least once to reach an alcohol content that is high enough that the spirit can be filled into casks.

Now what happens to the water during distillation? You can find the answer on your own, if you heat up some tap water in a pot and let it all boil away. You will be left with a grey residue made up from the minerals in the water. In the days before invention of ion exchangers, de-mineralized water was made by just distilling water.

During the distillation of whisky, the water in the still doesn’t even boil, so it will be fair to assume that the final spirit will contain pretty pure H2O in addition to the alcohol and aromatics. But even if some of the minerals can make into the spirit nevertheless, their effect on the flavour would only be minimal because the concentrated aromatics would overshadow it by far.

Take this and the fact that most whisky is diluted before bottling with regular tap water (without chemical additives, of course), and you will see that not much is left of the characteristics of the distillery water source.

Peaty Whisky From Peaty Water?

Now here’s a misconception that is about as persistent as the infamous Craig Shergold chain letter from the early days of the internet.

Every once in a while, newspapers, magazines or blogs inform us that the peaty character of Islay whisky is supposed to be an effect of the peaty water used in the distilleries.

Everyone who has at least a basic knowledge of whisky making should immediately know that this statement is pure rubbish. The water used by some Islay distilleries may well be peaty. But peaty water does not taste anything like peaty whisky. In fact the peat tastes more or less of nothing.

The phenolic flavours of  peated whiskies are solely caused by the peat smoke that is used during the malting process when producing peated malt.

What is the reason for such misconceptions? I guess it is mainly because articles like this one are written by people who only have a semi-education about whisky. Usually it’s the “wine guy” of a newspaper or a general food blogger who does not properly research the facts they use in their articles.

Image by Snap® via flickr

{ 8 comments… read them below or add one }

gal July 7, 2010 at 8:28 pm

great post oliver.

keep it up!


Wulls August 1, 2010 at 4:45 pm

Interesting topic…..
A few weeks ago I was passing through Fort William in the north west of Scotland and stopped off at the Whisky shop….
There I witnessed the shiop assistant gaily educating the foreign customers that the peaty water used in the whisky was what gave it its smokey taste!!!!!
Forthermore if you used peaty water to dilute the whisky it would taste even more peaty…..
seldom have I ever heard such crap. I emailed their head office with the story and have heard nothing back in two weeks.
Obviously they don’t care about misleading customers…….


Maie September 1, 2010 at 9:40 pm

Hi Oliver

I really like your topic about something that is very much often (in a lot of books) explained in a very wrong way.

Saying that, I don’t agree about the following quote “The phenolic flavours of peated whiskies are solely caused by the peat smoke that is used during the malting process when producing peated malt.”

I cant agree fully to this because : phenols are also collected during distillation. When it comes to the cutting point of the new spirit, you will see often that, for peated whiskies, it will be lower (around 59-60% alc/vol) then for unpeated ones (61-63). This because the phenols related to peated will be found at this stage of distillation.

If you talk with distilleries making peated and unpeated malts you often will find this too.

On the other side, the still itself and the level of filling can also interact in the level of phenols in the new spirit. Phenols, and their subdivisions, benzenes, will be removed by extensive contact to the copper.

On the other side, unpeated malt with a low cutting point will still show phenols that make you think of peated whiskies in their flavor profile.

Saying that, I would like to give an example. Peated Malt from Laphroaig for instance will have 40 ppm, the new spirit will just be at 25-22 ppm for the explained reason.

Kindest Regards



Oliver Klimek September 1, 2010 at 9:58 pm

I have to admit that so far I haven’t considered what might happen to existing phenols during distillation. It could well be that they are enhanced. And it might also be possible that a small amount can even be formed by recombination of other components in unpeated whisky. But I think these details are about as anorak as you can get 😉

But I think you will agree that peaty water alone just doesn’t give you peaty whisy.


Maie September 1, 2010 at 10:06 pm

oh no, you are right : peated water dont add nothing. You may know that Scapa used for a very long period the most peated water in the industy…

And, sorry, I don’t consider myself as an anorac, I maybe should, you’re right 🙂

And, Oliver, very good blog, very good questions to Serge (found your website because of whiskyfun)

keep on going with your very good site (liked specially the article about Kilbeggan, even if i am big fan of Cooley)


Mario (I’m the guy behind Daily Drams, may have found them on Seges website)


Oliver Klimek September 1, 2010 at 10:13 pm

Hi Mario,

I’m glad you like my blog. I’ve heard and read about Daily Drams, but haven’t had the opportunity to taste one of your bottlings yet.


Dieter November 3, 2011 at 1:17 am

Hello Oliver,

thank you for providing so much information about whisky. Funnily I just read your article “Professional Writers, Learn Your Whisky Basics!” before this one and then stumbled across this sentence:
“Due to the deliberate imperfection of a pot still, there still is a certain amount of water vapour finding its way through the condenser, so the process has to be repeated at least once to reach an alcohol content that is high enough that the spirit can be filled into casks.”

This has nothing to do with the imperfection of a pot still, rather than “imperfection” of physics. Look at the VLE (Vapour-Liquid Equilibirum) data of water/ethanol, for example a Txy diagram. It’s not like all the ethanol vapourizes first. It’s always a water/ethanol mixture vapourizing that is in equilibrium with the liquid phase.
In fact the imperfection of a pot still leads to a higher alcohol content due to rectification effects.

While I’m at it: “During the distillation of whisky, the water in the still doesn’t even boil…”
I think there is a general misunderstanding. You cannot look at the water itself. The mixture does boil. The vapour has a higher alcohol content than the wash due to the vapour-liquid equilibrium. Therefore the alcohol content in the wash decreases, which leads to a higher boiling temperature of the mixture. You’re still right about the minerals though, since they are solids (in the regarded temperature range).

Just my 2 cents about “Hobby writers, learn your thermodynamic basics!” 😉

Best regards,


Oliver Klimek November 10, 2011 at 12:43 pm

With the ‘imperfection’ I was basically referring to the difference of a pot still to a continuous still that allows distillation up 90+% ABV by design. From the thermodynamics point of view you are of course right.


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