Lesson 6 - Sensory Analysis
This lesson deals with the sensory analysis of beer. It details how to set up the elements of a sensory panel, such as panel selection, training, and the design of the sensory facilities, and then covers how to run the panel and collect the results. It discusses the various types of sensory test and their benefits before going on to cover the use of statistics to convert sensory data into information about the sensory quality of beer. Finally, it looks at the presentation of results from sensory tests and lists key flavour compounds in beer.
A – not-A test
In the A – not-A test our assessors are given a sample labelled ‘A’. They are allowed to familiarise themselves with the sample for as long as necessary. As soon as the test is underway the assessor no longer has access to ‘A’.
In most cases, sample ‘A’ is a control or reference sample and is well known to the assessors and is likely to be produced regularly in the brewery. A series of samples are then presented to assessors and they are asked to determine if they are ‘A’ or ‘not A’ samples. At least two minutes is allowed for the evaluation of each sample. The order of samples presented must be random and it must be different for all assessors. The number of samples presented should be lower for beers with strong aftertastes or complex flavours. We use 30 assessors for the A – not-A test.
There are variations to the test where the initial ‘A’ sample can be retained by the assessor and where familiarisation with the ‘not A’ sample is allowed. Another permitted variation is to have varying ‘not A’ samples.