The Science of Water and Whisky – Part 4 Impact of Different Water Qualities on Bowmore

I am often asked how important the quality of the water is when adding water to whisky.  I always recommend using clean potable water without any aroma or taint. Generally, this can be well-run local tap water if of a high enough quality, or bottled water in parts of the world where tap water may be suspect or tainted.  However, until now I had not fully explored the sensorial impact of different potable water properties on mixing with whisky.

Water Composition

Drinking water composition varies across the world dependent primarily on the geology of the land from which it is sourced.   Water is a lot more than just H2O. All natural water (undistilled) contains salts, acids, alkalis and many gases making it a highly polarised liquid. During recent studies, I have found that changes in the chemistry of the additional elements can have an impact on the flavours unlocked from single malt whisky on mixing, impacting the perceived balance of aroma, taste and texture.

In the MBD Laboratory, we have tested Bowmore 12 years old with the addition of three different potable quality waters, and have been surprised by the impact subtle differences in the chemistry of the water have had on the different flavours, tastes and textures unlocked from the whisky on mixing.

The three waters tested were:-

  1. Mineral-rich, with above average concentrations of Calcium and Magnesium minerals, high hardness and an elevated pH of 8.
  2. Soft water with low conductivity, hardness, minerals and polarity with pH 7. 
  3. Acidic water with higher Sodium chloride and Potassium sulphate, lower Calcium and Magnesium   and pH 6-7.

When the three waters were tasted individually, the differences in taste were very subtle, more noticeable as slight textural differences than taste.  From the initial taste of the waters alone, it was expected that differences in taste would be virtually indiscernible on mixing with Bowmore 12 years old.

Bowmore 12 years old and Water

When the three qualities of waters were separately added to Bowmore 12 years old, the sensory qualitative changes were much greater than had originally been expected based on subtle taste differences in the waters alone.

Below is a collation of the observations made by members of the MBD sensory panel when the same quantities of the different qualities of potable water were added to Bowmore 12 years old.  All sensory testing was carried out blind.

1 part water: 1 part whisky

Bowmore 12 yo

with Mineral Water

Bowmore 12 yo

with Soft Water

Bowmore 12 yo

with Acidic Water



Chalky and floral with peaty minerality

Sweet and soft fruitiness with less peat

Astringent, subdued peat with tarry-solventy notes


Intense with floral and chalky dryness, lemon sherbet, mint and violets

Lemon-citrus, beeswax-honey, vanilla, almond nuttiness, waxed fruits

Brine, cereal, nose prickle, peppery


Textural – effervescent chalkiness, dissolves on the tongue, subtle dryness/alkalinity at the back of palate 

Mid-palate sweetness, more fruit complexity- vanilla, peach,  lemon, honey.

Less iodine

Tangy brine, iodine, salty and bitter, acidic unripe fruits, hint of cereal



Long and floral minerality, chalky, dry

Smooth waxy mid-palate fruitiness

Integrated peaty/cereal notes. Most peaty

 Summary of our findings

  • The mineral-rich water unlocked additional layers of floral, herbal and peaty notes on the nose, and provided a more intense and intriguing textural experience (chalky minerality) on the tongue.
  • The soft water brought out more of the sweet honeyed and citrus fruit notes, and delivered a softer, sweeter and smooth rounded taste experience.
  • The acidic water brought out more peppery peat, iodine and brine with unripe fruits and cereal notes.

Which water and Bowmore combination you will prefer is all down to personal taste. If you prefer a sweeter honeyed taste, adding soft water may be preferred. However, if you prefer the drier/briney tastes in Bowmore, a slightly acidic water (such as the water sourced locally on Islay) may be preferred.

I would encourage the drinker to explore Bowmore with water and enjoy the multi-faceted and enigmatic taste journey that will develop as different flavours are revealed moment-by-moment as water is added.  As this experiment has concluded, you are very likely to discover different facets of Bowmore’s highly complex and enigmatic flavour profile with subtle differences in water chemistry.


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