While pH is known to vary between different variety of whiskies it lacks a statistically rigorous exclusionary standard to be used as an authentication marker for Scotch whisky.
This study (open access) addressed this gap by performing statistical distribution fitting analysis on the pH of 32 authentic single malt and 33 authentic blended Scotch whiskies on the market in Taiwan, utilizing the three-parameter lognormal distribution to establish the 99.7% authentic pH ranges for the first time: 3.47–4.46 for single malt and 3.73–4.67 for blended whisky.
Validation using seized counterfeit samples confirmed that an abnormally elevated pH is a strong indicator of adulteration.
Consequently, this authors propose using a pH threshold as a rapid, non-destructive, and cost-effective forensic exclusionary criterion. Although the pH value feature alone is insufficient to confirm authenticity, it is ideal as a first screening test.
Photo by Ambitious Studio* | Rick Barrett on Unsplash
