Medium chain fatty acids arise from the metabolic activity of the yeast. Their concentration depends upon the yeast strain, fermentation temperature, intensity of wort aeration and duration of lagering the beer.
Determination of the free, volatile fatty acids in beer and wort
The method is suitable for wort and beer of any original gravity and alcohol content.
Volatile substances in beer are concentrated through distillation and the distillate is extracted using dichloromethane. The solvent phase is concentrated in the rotary vacuum evaporator and subsequently analyzed using a gas chromatograph. The linearity of the detector and the determination of the concentrations of analytes in the sample is achieved by using multiple concentration levels within the relevant range and through evaluation of the relative area under the peaks.