Draught beer hygiene: a forcing test to assess quality

作者：Mallett James R.; Stuart Melanie S.; Quain David E.^*

来源：Journal of the Institute of Brewing, 2018, 124(1): 31-37.

DOI：10.1002/jib.470

• dispense
• beer spoilage
• quality
• method

The quality of draught beer is important to consumers but can be inconsistent, ranging from excellent through to unacceptable. The few, dated studies of draught beer quality have focused on the number of microorganisms that are present in the product. Work reported here suggests that this approach has its limitations and fails to relate to beer quality post-dispense. An alternative approach using the long-established forcing' method provides a better but still retrospective assessment of draught beer quality. Samples post dispense are forced' by static incubation at 30 degrees C for four days and beer quality is ranked by the measurement of absorbance at 660 nm. The increase in absorbance reflects the growth of beer spoilage microorganisms present in the beer at dispense. Four quality bands are proposed, where quality is described as excellent (absorbance increase of <0.3), acceptable (0.3-0.6), poor (0.6-0.9) and unacceptable (>0.9). The method is straightforward, requires no special skills and enables, for the first time, the robust quantification of draught beer quality. It is anticipated that the method will have widespread application in the measurement and improvement of the quality of draught beer.

• 出版日期2018