Lesson 7 - Sensory Analysis SAQ

**You are a consultant brewer working for a new beer competition, the International World Beer Challenge Cup. The organisers are keen to make the results of the competition as ‘scientific’ as possible. The beers of each category will be assessed using ranking for preference, followed by a group discussion to decide on winners. The judges will be brewers and beer writers and will sample four categories over a day with ten samples per category. You have been asked to design a basic sensory screening and training day for the judges. Outline your design for the day and explain potential problems with the data which may arise from the way the competition is set up.

Response:

Screening:

A short questionnaire should be given to the judges to establish if they are free from diseases and/or allergies which could affect sensory capabilities. It will also be necessary to check that they are not taking medication with side effects which affect taste or smell. It should be established if they are smokers. Although smokers can sit on a commercial sensory panel, smoking directly before a panel is not permitted. As they will be sampling beer all day it is likely they will smoke at least once before a set of beers are evaluated. In addition, the smell of smoke on their clothes has the potential to affect the tasting environment for other judges. Their usual consumption of alcohol is perhaps not so much of a concern as it would be for a regular sensory panel (particularly as they will be sampling 40 beers over the day) but it would be prudent to ask them their daily alcohol intake to ensure none are dependent alcoholics.

Next, the panellists should be screened for anosmia and ageusia by use of flavour standards. There will be insufficient time to train the panel before screening. In any case, if the judges have been selected for a prestigious competition, they should have a good level of sensory knowledge and should be able to identify key flavour and aroma compounds. Screening should be with a range of flavour standards which reflects the aromas and tastes of the beers to be evaluated. The standards recommended by the EBC for descriptive analysis would be a good selection. These should be spiked in a light tasting beer (US lager style). A recommended success rate of over 75% would be advisable given the experience of the judges and the importance of the competition.

Training:

Training should cover two aspects. The first would be regarding conditions for the day and cover what the judges need to do and not do the night before and on the day. No more than two alcoholic drinks and no spicy foods the night before. No spicy foods and no strong perfumes should be the rule for the day of judging. No mobile phones or tablets will be allowed in the judging.

The second aspect of training should be familiarisation of the panel with the preference ranking test to be undertaken. Finally, the ground rules of panel discussions should be laid out to the judges to limit the effect of strong and weak personalities.

The judging, screening, and training should be undertaken in a room free from noise, disruptions, and odours. Judges should also be trained to work in isolation at all times except group discussions.

Potential problems with data:

Because of the number of samples, sensory fatigue is likely to be a big factor. Towards the end of the day the judge’s capacity to work error free will also be a significant factor in the accuracy of the data. The samples are to be discussed so the order of presentation and the codes used to denote each sample will be the same for all judges; again, this will introduce bias into the results. The group discussion will be the biggest source of bias with prominent industry figures exerting influence over other tasters.