The Brenner test is the internationally recognized method for beer and wort bitterness measurement. In this method, degassed beer samples are extracted with iso-octane and the absorbance of the extract is determined at 275nm. The results are expressed as bitterness units (BU). But the Brenner test requires highly trained staff or special equipment. Alternatively iso-alpha-acids, including isohumulone, isocohumulone and isoadhumulone, are often analyzed by high-performance liquid chromatography (HPLC). Iso-alpha-acids are principal bittering compounds in beer and generally known to affect not only the bitter taste of beer but also the overall product quality. For more efficient control of BU and iso-alpha-acids contents in beer and wort, the automated method has been desired. In this study, we have developed a fully automated method for determination of iso-alpha-acids and BU in beer and wort. This method, a modified form of the Roy Cope's method(1), is based on the solid phase extraction regime coupled with HPLC analysis (SPE/LC). In this analysis, the solid phase extraction (SPE) was performed for initial separation, using octyl (C8) extraction column. After a degassed beer sample or wort sample was loaded onto SPE column, other compounds were removed from the column with 65% methanol, and bittering compounds were subsequently desorbed with 90% methanol for HPLC analysis. The eluate recovered from SPE column was directly injected onto the HPLC system. The HPLC system was equipped with an octadecylated silica column for final separation and the UV detector was operated at 275nm. HPLC analysis allowed quantitation of iso-alpha-acids and the total peak area detected on the chromatogram was highly correlated with the BU determined by the Brenner test. The SPE/LC system enables the simple and rapid analysis with satisfactory reproducibility, making this fully automated system ideally suited to routine analysis in brewery. (1) Proc. Eur. Brew. Conv., Maastricht, pp. 599-606, 1997.