Tuesday, March 18 2008
My Dog Has No Nose
So much wine, so little time to judge
One of my favorite jokes is a stupid kids jape:
My dog has no nose.
Really? How does he smell?
Terrible !
Well, it laid 'em out laughing when I was six years old. But smell is a funny sort of thing. It's commonly believed that human beings have an inferior sense of smell, compared to other animals. We don't. Human beings have a great sense of smell, not as good as a bloodhounds, but better than many other animals. It's the ability to identify and discriminate between those smells where we fall down. But with practise and a bit of direction most humans can train themselves to be decent smellers and by extension, good wine tasters.
So let's talk about Sensory Evaluation in wine tasting.
Sensory evaluation is a scientific discipline used to measure, analyse and interpret reactions to the characteristics of foods and materials as they are perceived by human senses. It is the conscious effort to identify and judge different sensations and components in an object–in our case, wine. Human beings are used in much the same way a scientist might use a laboratory instrument, such as a gas chromatograph.
Sensory evaluation encompasses all of the senses. It takes into account several different disciplines but emphasises the behavioural basis of perception, and as such is a gestalt approach to product assessment, where the organised whole is perceived as more than the sum of its parts.
The Human Senses
Typically we think of humans as having only five senses. Sensory scientists however, look at eight distinct, interrelated senses that are important in measuring and evaluating wine.
Vision
Seeing-A product's appearance. With respect to wine this can seem minimal, but if you sample a high quality wine with a tray of muddy-looking, defective wine samples in front of you, your perception of the sample can be prejudiced. Extensive studies in the wine industry hold this out. Darker colours are associated with more intense flavours even if there is in fact, no difference in the beverages.
Olfaction
Smelling-The aroma or odour volatiles. With gustation, it makes up the Siamese twins of taste.
Gustation
Tasting- Taste sensations released by soluble compounds.
Tactile Senses
Touch-The item's texture, mouth-feel, and body. In wine this is often related to the sensations produced by tannin.
Kinaesthetic Senses
Neuromuscular perception–Feedback from muscles, i.e., the perceived weight or density of an object.
Audition
Auditory information when a product is ingested. In wine, we want to hear sipping so we know we're getting the wine back retro-nasally, however, potato chips are the best example of how audition affects sensory evaluation. Potato chips are the size they are because that size requires that your mouth be opened wide while you eat and accentuates the crunching noise. It is also no mistake that they are packaged in crinkling bags to remind you of what you're eating.
Trigeminal Sense
Irritation or pain-Heat/Cold sensations. This is a chemical reaction we feel in, for example, the smell of horseradish, the heat of cayenne, the coolness of a peppermint.
Temperature
Heat, cold–Effects of trigeminal sense below the pain threshold
Uses of Sensory Evaluation
Wine producers evaluate and measure the taste, odour, texture, etc. of their products. A versatile instrument for this is the human sensory system. In the wine industry, sensory evaluation is used for:
Grading: Raw materials can be graded and standardised. This is often done completely by a sensory judgment. We are familiar with this in the commercial wine industry, where experts designate wines. The coffee industry utilises expert cuppers.
Quality Assurance: Human beings understand variations in natural products but do not tolerate them in processed foods. If the flavour of a familiar wine kit is changed, it may be rejected. Sensory evaluation is a critical tool for Quality Assurance personnel. It can be used to test for off-flavours, changes due to reformulation, the effects of changes in processing, the effects of storage under various conditions (shelf life studies), the effects of packaging, etc. In wine we need to understand the scope of natural variation in our product, to discern natural variance in new crop vs. past harvest, or to distinguish new crop acidity or other changes. When examining changes in any part of the process, from sourcing raw materials to packaging, sensory evaluation is used to note differences in the final product.
Correlate Sensory & Chemical/Physical Properties: What specific characteristics in an item give it its taste and smell and are there ways we can manipulate these? (E.g. what are the chemical changes that take place when a wine matures? Which ones affect the flavour? Can they be accelerated?)
Marketing: Sensory information can be vital in making marketing decisions. Data is needed about product preferences, product optimisation, consumer acceptance, etc. There is a difference between what you do to assess product quality and process and what you do to look at consumer's preferences. You never want to use trained experts to predict consumer behaviour because by virtue of their training they are no longer reflective of the general population.
Product Development: New product introductions are a primary target for sensory evaluation. Past practices, general guidelines and quantified laboratory measurements can only develop a product so far, and beyond that it has to be rated on its sensory merits.
Sensory Evaluation is not just used in the wine industry. It is applied to cosmetics, perfumes, tobacco products, animal foods, and cleaning products. There are lots of areas where research is used: developing a new car smell product for used car dealers; a fresh-baked cookie air treatment product for Realtors to use when showing homes; fresh bread aerosols for markets, malls putting pizza aroma through air ducts to draw people to food courts.
If we are going to use humans as flavour measurement instruments we must understand how the sensory system works, how the brain processes information and how the human gives output.
Tomorrow: This Is Your Brain On Wine
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