Tag: blending-water

Most of what a distiller boils is water — a spirit still charged at 25% ABV is three-quarters water by volume, and a gin still is charged at 40–60% ABV on purpose. Charge strength is a deliberate setting that governs reflux, extraction and safety, and the water used to set it is a process input with its own specification. Here is why distillers dilute before they distil, and what that water has to be.

European wine law excludes the addition of water outright; American wine law permits it up to 35% of the volume; German beer law names water as one of four permitted ingredients; and EU spirits law allows it freely but regulates its quality. Four rules, one liquid — and the difference between them is entirely about when in the process the water arrives.

A 2025 study found PFAS in 95% of the American beers it tested, and traced them to the municipal water the breweries used rather than to anything in the brewing. Spirits are reduced to bottling strength with water too — often a third of the finished bottle by volume — and 2026 is the year the rules on that water started to bite on both sides of the Atlantic.

The same water can be described as 150 mg/L, 15 French degrees, 8.4 German degrees or 8.8 grains per gallon — and be classified "hard" by an American agency and "moderately hard" by a British one on the same day. Hardness is not one measurement but a family of conventions, and a buyer comparing water reports across markets is usually comparing units before comparing water.

Every bottle of whisky below cask strength is the result of one of two engineering choices. Either the spirit and the water met in a vat, were rested, gauged and corrected — or they met in a pipe, metered against each other in real time, with no second chance. The finished liquid can be identical. What the two routes demand of the water is not.

Drinking-water science says demineralised water is a bad idea — flat-tasting, mineral-poor, and corrosive to pipework. Regulators agree, and several set a minimum mineral content for treated drinking water. So why does every serious proofing specification run in the opposite direction, toward zero? Because the water in a whisky bottle is not the water in a glass, and the arithmetic that governs one has almost nothing to do with the other.