Determination of Free Fatty Acids in Wort and Beer

A method for quantitation of free fatty acids (FFAs) in beer and wort was developed. FFAs were extracted by a series of acidic chloroform/methanol and potassium hydroxide extractions. The esterification was performed by treating the extract with boron trifluoride/methanol. The FFA methyl esters thus formed were separated by gas-liquid chromatography and quantitated using three internal standards. The method was used to compare the FFA levels in clear (filtered) worts and trubcontaining worts, to determine the rate of FFA uptake by yeast during the initial stages of fermentation, and to determine the effect of storage and storage conditions on the FFA levels in finished beers.