Organoleptics in operation: how can they help?
Tasting and evaluating wine is always a particularly exciting challenge. For many winegrowers, tasting is a key tool, whether it is to determine blends, consider fining treatments, or market analysis. They are not at all easy, though. Competition tastings and quality controls are very painstaking processes that follow precise specifications. Strict scientific wine tasting is much more complicated than either representable or necessary in everyday life. Honestly, when did you last think more seriously about what goes into it? Organoleptics is ultimately a blend of knowledge and perception. It makes it possible to categorise certain impressions more accurately and to draw conclusions that stand up to scrutiny. The evaluation’s accuracy and reliability depends on two factors: what is perceived and how is it categorised? A lot has happened in research. Umami (meaty-savoury) was identified as the fifth taste and a more accurate positioning of taste perception (Fig. 1) was established, the perceptibility of fatty acids as a separate sensory impression is currently being investigated.
Greater experience and more expertise can quite definitely improve classification of aromas. Whether an aromatic impression is positive or negative can be learnt and also deliberated from case to case. Grassy notes, in red wine for example, can quickly seem troubling, but are quite typical of cer-tain white wines, such as Sauvignon blanc. Perception, on the other hand, is largely genetic. Stimulation thresholds for aromas vary greatly from person to person. This can be easily compensated for, if several people taste together. Two or three opinions quickly highlight obvious commonalities or deviations. Whilst marketing departments and wine critics usually opt for a descriptive wine tasting, a comparative tasting is more advantageous for producers. Which blend exhibits the best balance? Which sample offers the best integrated acid? What tannin dosage would be ideal?
It is not a question of a detailed translation of an individual wine’s properties in words, but of relating various wines to each other overall, or in a single aspect. Such a tasting can be very simple and enquire about personal preferences. Which of the three versions of a wine is preferred? This quickly achieves a result. It is possible to see whether there is a clear favourite, or disagreement. However, this method does not detect whether the version chosen also offers an objective difference that is clearly perceptible to all consumers. Indepth comparison, forwards and backwards tasting of different versions all too often results in discussion of tiny facets. After multiple tastings and deeper involvement, these are easier identified and given greater weight more quickly than by “fresh”, impartial tasters. It is then necessary to check, whether the differences are obvious to the consumer as well. A simple triangle test can help in this case. Two wines, such as the barrel sample and the version of the intended blend, are poured into three glasses: can the singular wine be distinguished in a blind tasting? Can the double sample definitely be detected? A genuine difference can only be declared when a clear, reproducible attribution can be achieved (Fig. 2). Otherwise, the changes brought about by blending or fining are too slight to be relevant. As every tasting is also a snapshot, ideally a decision should not be taken immediately after the first round. The preliminary tastings should not take place until the measures taken have had time to integrate. Regardless of whether blending, deacidification or tannin addition has been simulated, how the samples smell and taste a day later provides valuable insights into the decision’s consistency. It is important that the samples are tasted in as similar a way as possible and that changes, such as oxidation, are precluded. A small bottle, filled to the top, tightly closed and stored in the refrigerator, is generally stable for several days.