A 40% ABV whisky does not freeze until roughly -23 °C, and even then it turns to slush rather than solid. The reason is arithmetic on the water-to-ethanol ratio — and it explains why the mineral content of blending water is irrelevant to freezing, while its quantity is everything.
A certificate of analysis that arrives after the proofing tank is a receipt, not a control. Once purified water has gone into spirit, most of the corrective actions a food safety system assumes are available have already closed — a strength error can be rescued with arithmetic, a taint cannot be rescued at all. Here is where the decision point actually sits, what a non-conforming batch can legally become, and why blending water is a goods-inwards problem rather than a bottling-hall one.
Water is the largest ingredient in a bottle of Scotch by a wide margin, but it did not all arrive the same way. Some of it came over the lyne arm as vapour and is distilled by definition; some was added at the filling store a decade before anyone tasted the spirit; and the largest share was poured in at the bottling hall, minutes before the cork went on. Trace each drop and roughly three-fifths of the water in a standard 40% bottle never went near a still.
Most of the world's gin is made as a botanical concentrate and reconstituted later with neutral spirit and water. The law permits it explicitly, a blind panel of 54 could not tell the difference, and the arithmetic is startling — in a 1:4 multi-shot, roughly seven-eighths of the finished bottle never shared a still with a juniper berry, and the single largest component is water added at the reduction tank.
Equilibrium does not care which liquid you pour into which — a 40% ABV spirit is a 40% ABV spirit however it got there. But the journey is not reversible. Along the way, parts of the liquid pass through strengths the finished product never sees, and some of what happens in those moments never undoes. Here is what the evidence actually shows about order, rate and agitation, in a proofing vat and in a glass.
Pour water into pastis, ouzo, raki, arak or absinthe and it turns white in seconds — no shaking, no emulsifier, no heat. It is the same physics that makes an unfiltered whisky go hazy, running deliberately instead of accidentally. Here is the mechanism, the arithmetic of how little anethole water can actually hold, and the evidence that the temperature and mineral content of the water you add change the cloud you get.