Reviews

Sensory analysis, or How to guarantee a wine’s taste
www.drinktime.ru, 13 May 2009

Imagine that you are the owner of a chain of wine shops and wish to launch own wine brand.

A dozen of suppliers are already queuing for a contract. But you want to make sure that new wine will be popular with consumers — like brand X by winery Y. How to achieve if not an identical, but a very similar taste to the bestselling wine?

This is a real situation with which retail wine buyers in Europe and other parts of the world have to deal. Producers who want to maximize their sales are also familiar with it. For help, they go to laboratories of sensory analysis.

Wine is among the most popular products for sensory research, but it is not unique. These laboratory services are also demanded for hygiene products, perfumes, makeup and even clothes.

What test does a wine undergo to receive an objective sensory report? Can sensory quality be objectively evaluated at all? Michela Cipriani positively responds to the latter question. Her business card says that she is a sensory coach working in the laboratory of Italian wine producers Unione Italiana Vini. Her lab is known as one of the most innovative and technically advanced in Italy.

Michela tells that in late 1950s sensory analysis became a scientific discipline based on valid statistical data, rather than on subjective human emotions. In other words, if a test in conducted in Italy, France of Russia, the results will be the same irrespective of the country.

One doesn’t have to be an experienced taster to get on the sensory analysis panel. Normal people, i.e. ordinary wine consumers, are recruited. One should simply be able to distinguish between usual sensory cues, and every member of the panel is tested beforehand.

Here, for example, is a taste test. A panel judge needs to identify which of the five tastes (sour, sweet, salty, bitter or umami) is added to neutral water. The number of glasses with clear liquid may be more than five. Some tastes can be repeated, and pure water can yet be pored in other glasses. Concentrations are not high, and the test is not as simple as it may appear. Sweet and bitter tastes are confused most often. If a person makes a mistake, he is expelled from the panel.

The next level tests tactile perceptions. Our tongue is covered with papillae which distinguish between astringency, burn, suppleness, tannins and other types. Water diluted with glycerin gives a sensation of suppleness, while alcohol — of burn. Astringency and tannicity are similar but not identical. Astringency creates dryness on the tongue, while tannins give a slightly different sensation. Tannins are present in tea, wood, grape skins and seeds. Experienced tasters can identify tannins from grapes and from wooden barrels.

It is much more difficult to perform a tactile test. Not many people pass it successfully from the first time, but one shouldn’t despair. Tactile receptors, like all others, can be trained.

Aromas are a fundamental feature for sensory quality. They say that our positive or negative perception of wine depends by 80% on a wine’s bouquet. To see the point, drink some wine while blocking your nose. You will hardly feel anything, and this is why it is pointless tasting wines if you have a cold and a blocked nose. You will simply not be able to feel difference between a good and a bad sample.

Tasters use an “Aroma wheel” diagram to identify aromas for sensory analysis. Aromas are grouped in several big families, each being subdivided into smaller groups. For example, the family of fruity aromas is divided into citruses, berries, tropical fruit, etc., and lemon, grapefruit, orange and other nuances are distinguished among citruses.

Aroma test is not easy either, but only because smell is not as vital for survival nowadays as sight or hearing. Regular training can turn any person in a good taster.

Then starts a routine work which many of us find boring, but which effectively provides data for sensory analysis. Each taster gives a subjective written description of wine’s appearance, aromas, flavours and aftertaste. All descriptors are put together in a general table. The most popular are singled out and further rated by intensity. Each sample is tested 2-3 times to avoid mistakes, and the data is processed.

The result is a graphic sensory profile, where aromas and flavours of wine can be easily picked. To make a wine according to the given parameters will then be a matter of a winemaker’s experience and skill.