Tag: quality-control

A blending water can pass conductivity, TDS, pH and microbiology and still carry an earthy or antiseptic note straight into the bottle — because the compounds that cause it are active at nanograms per litre, below what routine instruments report. The drinking-water industry solved this with formal sensory methods decades ago. Here is how they work, what a trained panel can detect that a lab cannot, and how a distillery should smell its water before it proofs a cask.

Before a quality panel judges a cask, the sample is cut to 20% ABV with purified water. It is not a house preference — it is the documented standard practice of the Scotch whisky industry, and the published evidence shows it is the strength at which a trained nose is most likely to catch the fault that would otherwise reach the bottle. At that dilution, the water is roughly half the sample being assessed.

Every reduction begins with a number you did not choose — the measured strength of the cask in front of you. Get that number wrong and every litre of blending water you add afterwards is wrong too. Here is how strength is actually measured, why the thermometer matters as much as the hydrometer, and why an aged whisky reads weaker than it truly is.

Every spec sheet for blending water argues about minerals. Almost none of them mention the organisms. Demineralisation removes calcium and chloride; it does not remove bacteria — and by stripping out the disinfectant residual along with everything else, it hands the survivors a system with no defences. Here is what actually lives in ultrapure water, which parts of a purification plant grow it rather than remove it, and what a trade buyer should ask for beyond a TDS number.