Discriminating counterfeit beer with Raman spectroscopy and PCA

Importance of the Topic

Beer counterfeiting poses significant health and economic risks; traditional identification methods are limited. Raman spectroscopy offers a rapid, non‐invasive approach to authenticate beverages by detecting subtle compositional differences reflecting unique brewing recipes.

Study Objectives and Overview

This study investigates the capability of the i‐Raman EX spectrometer with 1064 nm excitation, combined with principal component analysis (PCA), to distinguish between four popular lager brands and a binary mixture, demonstrating a method for detecting adulteration and counterfeit products.

Methodology and Instrumentation

Samples comprised four lager beers: Lager-H (150 kcal, 5.0 % ABV), Lager-B (145 kcal, 5.0 % ABV), Lager-C (149 kcal, 4.7 % ABV), and Lager-M (96 kcal, 4.2 % ABV). Raman spectra were acquired by immersing an RIS100-SS sapphire‐ball probe in decanted beer. Instrument settings: i-Raman EX, 1064 nm laser, 330 mW power, 10 s integration, single scan average. Data processing used BWSpec and BWIQ software; PCA enabled sample classification.

Key Results and Discussion

Spectra are dominated by water and ethanol, with the C–C stretch at 880 cm⁻¹ correlating to alcohol content. PCA score plots reveal distinct clusters for each brand. A 1:1 mixture of Lager-H and Lager-M forms a separate cluster, confirming the method’s sensitivity to detect blended or counterfeit products. Lager-M (light beer) is clearly separated due to its lower ABV and caloric content.

Benefits and Practical Applications

• Non‐destructive, reagent‐free analysis
• Minimal sample preparation using an immersion probe
• Portable system suitable for on-site authentication
• High sensitivity to detect adulteration and mixtures
• Applicable in brewery QA/QC, customs, and law enforcement

Future Trends and Potentials

Emerging developments include integration of machine learning for automated classification, expansion of spectral libraries to cover diverse beverage categories, real‐time inline monitoring in production, and multimodal spectroscopic combinations to enhance selectivity and robustness.

Conclusion

The i-Raman EX system paired with PCA provides an effective, field‐portable tool for authenticating lager beers and identifying counterfeit or adulterated products, supporting consumer protection and quality control efforts.

Reference

• 14.8 million litres of alcoholic drinks seized across Europe, EU Anti-Fraud Office, 2022.