Large brewing companies which operate several breweries must coordinate their quality control activities between breweries to maintain uniform company wide quality standards, particularly for beer brands produced by more than one brewery. A flavour quality evaluation system for large companies, developed by South African Breweries, is described. Each brewery has a pool of trained tasters from whom a panel is drawn for each taste testing session. At least once a week, random samples of freshly packaged beer are evaluated by the tasters to determine whether or not they conform to the standard of quality expected of their brands. To facilitate the diagnosis and correction of the causes of quality problems, any taster who marks a sample as "defective" must give his or her reasons for doing so in writing. Written comments in support or explanation of panel members' evaluations of samples are also encouraged (though not compulsory) even when samples are considered of acceptable quality or better. A central taste panel, drawn from a pool of specially selected, highly skilled and experienced tasters, who must undergo additional training and a period of probationary membership before they can be accepted as full members of the pool and are subject to continuous performance review, evaluates a smaller random set of samples taken from all the company's breweries. Each panel member produces an individual flavour profile and "drinkability" rating for each sample. The individual evaluations and the results of a comprehensive analysis of the sample are then discussed by the whole panel. The central panel maintains a check on the performance of the brewery panels and, in the case of brands produced by more than one brewery, ensures that any tendency towards interbrewery variations in a brand is detected and corrected as soon as it begins to appear. The system for recording trends in taste test results is also explained. It uses a so called "box and whisker plot" which enables the median value, the spread of results around the median, and the maximum and minimum values to be displayed together on a graph, making it easy to evaluate the long term consistency of product quality and observe any changes over time.
Keywords : beer brand brewery quality control statistical analysis taste panel taste test