WCPS: Elemental Analysis of Beer by ICP-OES

Significance of the Topic

Metals present in brewing water, grains, hops and process equipment can influence beer flavor, stability and safety. Monitoring trace and macro elements during wort production and final beer is crucial for quality control, process optimization and compliance with taste specifications.

Objectives and Study Overview

This study aimed to quantify calcium, potassium, magnesium, sodium, copper, iron, manganese and zinc in wort and finished beer samples from New Belgium Brewing Company using the Agilent 5110 Vertical Dual View ICP-OES. Four wort and corresponding finished beer samples representing different beer styles were analyzed to assess elemental changes during fermentation and processing.

Methodology and Instrumentation

Sample Preparation:

• Sonication of 10 mL beer or 8 mL wort for 20 minutes to remove dissolved CO₂.
• Dilution: beer 1:1 with 14% HNO₃; wort 1:4 with 8.8% HNO₃ and 3.8% ethanol.
• Filtration through Whatman paper before analysis.

Calibration and Quality Control:

• Multi-element standards: 0.1–0.5 ppm for Cu, Fe, Mn, Zn; 15–50 ppm for Ca, K, Mg, Na in 7% HNO₃/3% ethanol matrix.
• Internal standards: gallium (200 ppm) and yttrium (40 ppm).
• QC checks: continuing calibration blanks and verifications, low/high concentration spike recoveries within ±10%.

Used Instrumentation

• Agilent 5110 VDV ICP-OES with SeaSpray nebulizer, double-pass cyclonic spray chamber, 1.8 mm injector torch.
• Operating parameters: RF 1.2 kW; plasma flow 12 L/min; auxiliary flow 1 L/min; nebulizer flow 0.7 L/min; axial and radial viewing modes for minor and major elements.

Results and Discussion

Detection limits for all elements were in the sub-ppm range with method detection limits (MDLs) below typical wort and beer concentrations. Calibration linearity exceeded R² > 0.999 for all wavelengths. QC spike recoveries ranged from 92% to 107%. Quantitative analysis showed:

• Major elements (Ca, K, Mg, Na) increased from wort to beer reflecting salt additions and process water composition.
• Iron and copper remained at low ppb to sub-ppm levels to prevent off-flavors.
• Zinc and manganese were consistently monitored to support yeast health.

Semiquantitative IntelliQuant profiling revealed unexpectedly high silicon levels, indicating grain and husk contributions throughout brewing.

Benefits and Practical Applications

• Rapid multi-element analysis supports brewers in process monitoring and quality assurance across production stages.
• Ensures metal concentrations remain within sensory and safety specifications.
• Semiquantitative screening can identify non-routine elements such as silicon for nutritional or process insights.

Future Trends and Applications

Advancements may include real-time process monitoring with inline ICP-OES, integration with automated sample prep, expanded semiquantitative libraries for broader element coverage, and data analytics for predictive quality control. Coupling with chromatographic separation could enable speciation studies of metal complexes in beer.

Conclusion

The developed Agilent 5110 VDV ICP-OES method delivers fast, accurate and reliable determination of key macro- and trace elements in wort and beer. It offers brewers a robust tool for elemental profiling, quality optimization and process control.