Does water matter?

Small quantities of white powders and a straw beguiled guests at Camper English's presentation of his investigation into whether the quality and source of water actually makes a difference to distilled spirits.

In reality, the talk had nothing to do with Class A drugs and the powders were actually minerals for delegates to compare when mixed in various waters and with Bowmore whisky, but the premise of the talk was no less intriguing. With practically every distillery boasting about the quality of the water they use, does it actually have a tangible impact that their water is sourced from this aquifer or that undersea spring? And is that all of that then undermined when most distilleries tend to dilute distillates to bottling strength using municipal water supplies.

The limestone cave at Jack Daniel's; the aquifer used by Plymouth gin; the undersea Hawaiian spring water used in Ocean vodka: distillers from all spirit categories brag about the quality of their water sources, but then tend to dilute with municipal water that has been purified by reverse osmosis. "Why do we hear so much about water when it's not so much in the finished product?" asked Camper. "And why not distil with reverse osmosis water?"


His investigation took him to Japan, where a former master distiller from Yamazaki spoke to Camper about how they had themselves tested the impact of water on distillation, by swapping the water source from two distilleries and analysing the results.

It had a huge impact, with the distillates bizarrely manifesting the qualities of each other's terroire. On closer examination, Yamazaki concluded it was the minerals contained in the water that provide particular nutrients to yeast. "It's not the 'purity' of the water that's important, it's the minerals," said Camper, adding that breweries are typically located in hard water areas based on the knowledge that the minerals provide nutrients for the yeast. "Minerals help yeast create good, crisp flavours in beer, and those flavours will be concentrated during distillation."

Some distillers therefore add a mineral mix to their water to mimic the characteristics of water from particular geographic areas, such as Purity vodka, while Corsair distillery uses smoked water for some of its distillates. Cognac Ferrand ages water in casks before it dilutes its cognac to prevent 'shocking' the spirit - it becomes lightly alcoholic while it ages.


Turning to the white powders in front of delegates - small amounts of magnesium and calcium - Camper now led a tasting where the minerals were added to sparkling and still waters, and then added to Bowmore whisky. This manifested clear differences in flavour profile, not least by showing there are differences in adding water to whisky compared to whisky to water, with different flavour characteristics coming to the fore. Water added to whisky causes 'saponification', where heavier oils with cereal and earthy notes permeate through the water layer and evaporate off first; whisky added to water manifest 'esterication' that enables lighter fruit and floral notes to evaporate first.

Assuming that the mineral composition of water is integral to the taste of a spirit, then shouldn't we use waters that are closest in character to the spirit, argued Camper. Here, he was echoing a water tasting conducted by Bowmore master distiller Rachel Barrie. She detected floral, herbal and peaty notes in hard water; honey and citrus notes in soft water; and peat, iodine and brine in acidic water.

Camper went one step further, noting that these three water types tend to align to the taste profiles of waters from the Highlands, Speyside and Islay, and then identifying particular water brands that share those characteristics for mixing purposes.

Using published mineral rates, he concluded that Highland Spring is most similar to Speyside water/whisky characteristics; Fiji water and Mountain Valley are close to the Highlands; and Fiuggi water is most similar to Islay water.

In conclusion, says Camper: "I'd say that the choice of water in making spirits matters very much, but not in the way that we think, or that makers imply, because nearly all of that water is removed during distillation and replaced with highly filtered municipal water. It's the minerals in that initial water source that matter, not the pure H2O itself."

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