Aroma compounds with low to medium volatility, which are present in stronger concentrations in beer are detected and measured with this analysis method. Certain substances serve as indicators for the technical parameters measured during wort boiling, yeast pitching and aeration, during fermentation as well as for the physiological condition of the yeast.
The method is suitable for the determination of water vapor volatile aroma compounds in beer.
Volatile aroma compounds are driven out of the sample through steam distillation. The ethanolic distillate is saturated with NaCl. Potassium hydrogen sulfite is added to separate carbonyl groups that might interfere with the analysis. The extraction of the aroma compounds is performed by shaking out with dichloromethane and the phases separated by centrifuging.