Journal

Most of the world's spirits duty is levied on alcohol, not on liquid — so the 420 ml of water in a 700 ml bottle of 40% ABV whisky is the one ingredient the excise system charges nothing for. Much of India works the other way, assessing duty on the bulk litre of finished product, which puts every litre of blending water inside the tax base. Here is the arithmetic on both systems, what it does to bottling strengths and cask-strength pricing, and why an untaxed ingredient is the wrong one to buy on price.

A blending-water specification is a list of limits. A certificate of analysis is a list of claims that those limits were met. Between the two sits a set of standardised analytical methods — conductivity by a three-stage pharmacopoeial test, organic carbon by oxidation, trace ions by ICP-MS and ion chromatography, organisms by culture, and taste by a trained panel — each with its own blind spots. Here is what actually measures what, why two honest certificates can disagree, and the questions that separate an audited supplier from a confident one.

Every whisky-producing country regulates what may be added to the spirit, and almost all of them name water. Only one names where the water has to come from. Japan's labelling standard requires that "water used in production must be extracted in Japan" — a clause with no equivalent in Scotch, EU or American law, and one that quietly turns blending water from a process input into a matter of identity. Here is what the rule says, what it does not say, and why the geology behind it is unusually well matched to the claim.

A water softener takes hardness to zero, and a lot of people read that as "the minerals are gone." They are not. Ion exchange swaps calcium and magnesium for sodium and leaves total dissolved solids, alkalinity, chloride, sulphate and silica exactly where it found them — while adding sodium and a chlorine demand of its own. Here is what a softener actually does to water, why that is the wrong answer for spirit reduction, and the one place it genuinely earns its keep in a blending-water plant.

Indian Made Foreign Liquor is the category that dominates the world's largest whisky market, and its standard recipe begins by cutting 96% neutral spirit down to 42.8% with demineralised water. That single step makes water the largest ingredient in the bottle by volume — and, because an ENA base carries almost no congeners to hide behind, the one with the least cover for a fault.

Adding water to spirit releases heat and destroys volume — two facts that make every strength reading taken on a freshly reduced tank wrong. Here is the physical chemistry behind it, why the whole industry quotes strength at 20 °C (or 60 °F), how large the gauging error actually is, and what temperature your blending water should arrive at.