The Right Water for Whisky Tasting

1. An Important Additive to Single Malt Whisky

I often hear this sentence from Whisky lovers: "I drink my Whisky only neat." Should we leave this sentence uncommented? Surely not. But this sentence actually expresses a positive attitude towards enjoying Whisky: "I will not water down my precious Whisky!"

This article explains why you still might want to dilute your Whisky with a bit of water and which water is best suited.

The famous Highland Spring water in a green bottle
Highland Spring Water from Scotland (Green Bottle)
The famous Highland Spring water in clear bottle
Highland Spring Water from Scotland (Clear Bottle)

Without water there's no life. We can survive for 10 weeks without food since our body has built up nutrient reserves, but a few days without water are life-threatening. Our body consists predominantly of water, of which we constantly lose large amounts due to breathing and sweating. The average person uses up between 0.4 gal. us. (1,5 L) and 0,7 gal. us (2.5 L) per day, which they must replenish as soon as possible. When doing physical work or sports you easily need double the amount. Beside tap water, people in the Western world drink mineral water to cover this need. The average German, for example, drinks almost 26 gal. us. (100 L) of mineral water per year.

Water is the substance that regulates all the vital functions of our body. It is the solvent that guarantees the transport of nutrients and waste products. Water also regulates the body temperature. Sweat that evaporates on the skin cools the overheated body.

The waterfall behind the Arran distillery
Waterfall (Arran Distillery)

2. The Mineral Content of Water

Water is one of the most natural foodstuffs. The taste of mineral water ranges from completely neutral to heavily sour or salty. The taste comes from the solved minerals and other inorganic substances the water carries on its way to the surface. you fill a container with mineral water and immerse two metal plates in it, you can prompt the ions in the water to an ordered movement by applying voltage to it. The positive ions separate at the negatively charged metal plate (cathode). Therefore they're called cations. With the negative ions (anions) the same happens at the positively charged anode.


The most frequent ions are shown in the table below.



Mineral waters are divided into 'poor' and 'rich' types according to their mineral content. 'Rich' mineral waters can have a mineral content of up to 0.37 oz/gal (40 g/l). One of the 'poorest' types is the water from Hawaii with only 0.0006 oz/gal (5mg/l).

Among the mineral waters with less than 0.009 oz/gal (1g/l) are the well-known Volvic, Evian, Perrier and Vittel from France.

The most frequent cation and anion combinations result from the rock layers the water flew through.

Limestone Strata
Gypsum Strata
Saline Lakes

Sodium ions and chloride ions together form table salt. If a mineral water contains predominantly these components, it's going to taste salty. Salt consists of 60 weight percent of chloride ions and of 40 weight percent of sodium ions. So you just have to divide the amount of chloride in the water by 0.6 and you get the amount of table salt solved in the water. However, this is only true as long as the amount of sodium in the water is sufficient for the formation of salt. If not, you have to divide the amount of sodium by 0.4 to get the amount of table salt.

3. Dilution with Water

Whisky is usually filled into casks for maturation at 63.5% abv. When the whisky is stored for several years, its alcohol content usually decreases since alcohol evaporates through the cask walls. At the same time the Whisky takes up substances from the wood, which contributes to its flavour. Each year the alcohol content of the Whisky is reduced by 0.5% to 1%. When the Whisky is bottled it usually has between 50% and 60% abv left. However, at this strength the alcohol would still numb our taste buds on the tongue and in the mouth. Our sense of taste would be massively impaired, so we have to dilute the Whisky. High-quality Whiskies are more and more bottled at cask strength so the consumers can choose the level of dilution by themselves. Start at low strength (strong dilution) and work yourself up when your palate has become accustomed to the taste.

4. Choosing the Right Water

Which kind of water should we use to dilute Whisky? Should we use 'healthy', 'rich' mineral water? Or should we use 'poor' or deionised water that tastes like nothing? Should we use soda water, as we are taught in numerous spy movies, or does the Whisky become more interesting with sparkling water?

From my point of view there are two valid arguments:

1) Use distilled or deionised water to reduce your Whisky to drinking strength. Its neutral taste doesn't distort the taste of the Whisky. This kind of water is used to reduce Scotch Whiskies, which are bottled at 50% to 60% abv, to the required drinking strength. The Scottish Whisky law makes the use of this water compulsory for bottling outside of distilleries.

2) Scots use only fresh local spring water to dilute their best-loved beverage. When you order a Whisky in a Scottish pub, you also get a jug with spring water from the tap. So what could be more authentic than diluting the Scottish national drink with Scottish water?

Scotland is predominantly made of granite rocks and sandstone. Rain water that flows over or through these rock layers contains very few minerals, as the analysis below shows.

Unfortunately, most of the commercially available mineral waters have a much higher mineral content than the tap water in the Scottish highlands and on the isles. Look for the analysis results on the bottle when you choose your water. Also, please use only still mineral waters, since sparkling water would make the Whisky uneasy on the tongue and would influence the taste negatively due to the solved carbon dioxide.

Salt and hydrogen carbonate have the biggest influence on the taste of mineral water. The following table shows the classification of the waters presented here with regard to these two components. The mineral waters in the lower left corner are especially suited for the dilution of our beloved Single Malt Whisky. Best suited are original Scottish waters or the French still and ‘poor’ mineral waters and of course distilled/deionised water.


Not suitable


San Pellegrino

Highland Spring

Vitamin water




Warning: Never drink larger quantities of pure distilled water. The lack of ions can severely disturb your body's mineral balance and can even pose a threat to your life.

That's why you should always add an appropriate quantity of Single Malt Whisky to your distilled water. ;-)