Authentication of Pisco: from origin to alcohol content with Raman spectroscopy

Abstract

Validating authenticity, purity, alcohol content, and safety are common problems in the lucrative alcoholic beverage market, particularly when pricing is dependent on origin, variety, or alcohol content. The industry relies heavily on expert tasters and timeconsuming analytical laboratory testing to combat substitution and adulteration and needs better tools for field testing. Raman spectroscopy is stepping up to close this gap for Pisco, a premium Peruvian liquor, and has excellent potential to do the same for other spirits. Here we describe how one group at The Ohio State University are using 1064 nm Raman spectroscopy to distinguish between pure varieties and mixtures, and even identify the specific grape varietal. In addition to offering superior discrimination over UV-VIS, Raman also allowed quantification of both ethanol and methanol content in pisco, making it a wellrounded tool for quality assessment of spirits.