Water is an essential part of any spirit, and in many cases, a distiller’s chosen water will make up more than 50% of their final product. As such, many producers emphasize the source of their water, whether from glaciers, ancient aquifers or historic springs.

When making gin, water is used both to reduce the strength of the spirit entering the still, as well as proofing down the final distillate for bottling. But given that water from most supplies is filtered before its used, how much of the individual character really comes through in the finished spirit? As long as it is clean and pure, does the source of your water really make a difference?

Opinion on this subject varies greatly between distillers and is often (understandably) aligned with the choices that they have made for their own spirits. An independent investigation into the impact of using water from different supplies was conducted with the help of distiller Mark Gamble of Union Distillers. Six identical gins were produced with the only variance being the water used to dilute the spirit in the still and the final proofing before bottling.

The botanical recipe created specifically for the experiment was as follows: juniper, angelica root, coriander seed, lemon peel, orris rroot, cardamom, and licorice (a token amount).

Neutral grain spirit was diluted with each of the test waters to bring the spirit for distillation down to 50% ABV; then all of the botanicals were distilled from the pot. The resulting distillate was then proofed down to 40% ABV with the same test water, then ready to be bottled.

Six different waters were tested, originally as part of a talk at the London Distilling Expo in 2014 and then again six months later from sealed sample bottles from the same distillation runs. The following notes are from the second tasting.

All samples were tasted neat, without ice or additional water, at room temperature.

France Mineral Spring Water (pH 5.46)

Soft and clean, with some bright, floral notes coming through, as well as clean and crisp angelica and pine. This has a nice flow of flavors with a long, lingering, dry finish. Very sippable, with a silky and light texture.

Germanypring Mineral Water (pH 7.1)

This is bursting full of fruity, bright citrus from the coriander. The angelica is really prominent and hard to miss. Having said that, the overall flavor is less bold. The deeper pine notes are less prominent and dominated by the citrus. This has all of the characteristics of a contemporary gin, but was made and designed as a classic-style one.

Fiji Artisanal Spring Volcanic Mineral Water (pH 7.7)

This gin has a dry, but rich texture; it is not too sweet, but very smooth, and has bold juniper notes, as well as soft citrus and spice, then some of the sweet, root notes of the orris and licorice, before a dry finish.

Iceland Volcanic Glacial mineral water (pH 8.4)

Fruity on the nose, but this gin has a very short flavor profile, which is over almost immediately. There is a little burst of juniper, that quickly disappears. It also has a cloying texture, is rather hot at the end, and overall is not very pleasant to drink.

EnglandRecycled domestic water (pH 7.2)

Quite smooth and soft, with a taste that is concentrated in the middle of the flavor spectrum and thus lacks layers of flavor and complexity. It is a very dry spirit that sucks the moisture out of your mouth. Toward the end, more of the floral and perfumed elements of the botanicals come to the fore.

EnglandDemineralized domestic water (pH 7.0)

Full-bodied, with a smooth texture that really fills the mouth. While the intensity of the flavors is a little subdued, the integration of the botanical characteristics is very good. There are good levels of juniper, with some of the sweetness from the licorice and orris coming through, as well as a touch of citrus.

When the samples were first analyzed as part of a presentation at the London Distilling Expo, the difference between the spirits was subtle and largely confined to their texture and mouthfeel. Sample number 4 was notably thicker, rounder and more viscous than the others. Interestingly, as the samples have rested over the time, the differences between them increased, with a more noticeable impact on the flavor and some botanical characteristics becoming more dominant.

This significant change over time was unexpected. It requires a reinterpretation of the original results, which concluded that different water sources make a marginal difference. The effect of water sources on different flavor profiles over times becomes more meaningful. As all of the samples were stored in identical conditions, the more exaggerated variances are most likely due to the underlying mineral content of the waters (see Table).

The findings strongly suggest that further research is needed on the issue of the water used to distill and proof gin, but also underline the fact that, although gin is typically unaged, the spirit benefits from time to marry in the bottle.

Good gin comes to those who wait…