"Taste of light". When light damages wine.

"Taste of light". When light damages wine.

Jun 20, 2022


Ilaria Rosa

There are many people who, for convenience or convenience, prefer to buy wines at the supermarket; so far nothing wrong except that, almost all of these large distributions, store the bottles incorrectly. The bottles on the shelves are constantly exposed to artificial lights and sometimes even to sunlight, therefore UV radiation. This can compromise their quality and alter the organoleptic characteristics producing a defect better known as "taste of light".

This defect caused by prolonged exposure to light was first found in 1981 at the University of Reim, by Emanuelle Charpentier and Alan Maujean, while studying what caused the light on Champagne. The "gout de lumier" is found mainly in white wines and especially in those bottled in clear bottles that change and lose color; the wine thus tends to take on a really unpleasant smell that recalls cabbage, sulfur, rubber or onion , and also undergoes a very bad aromatic alteration. The color of the bottle greatly influences the conservation of the wine, in the transparent glass it takes two weeks of exposure to ruin it; in the green bottle it will take two months, while in the brown one it will take three. .

Red wine, even if exposed to UV radiation, does not undergo the taste of light because the presence of tannins protect it from this unpleasant defect.
Riboflavin, also called vitamin B2, is responsible for this chemical reaction that occurs in the presence of light; it reacts precisely to 375 nm in UV-A and 446 nm in visible, these wavelengths are emitted mainly by most neon lights and sunlight. Even in badly preserved beer it was possible to find this defect in the past, but fortunately a problem solved with the use of malts containing iso-alpha, hydrogenated acids, and the minimization of sulfur.

Recent studies have also given comforting results for wine; to reduce this problem, the use of hydrolyzable tannins was used to mitigate the formation of sulfur compounds, acting as electron donors and hindering methionine. There are many champagne producers who nowadays have adopted the special coating method, i.e. each bottle has been protected with a film that is able to reject UV rays.
Another factor that could deteriorate a wine is the ambient temperature: this should not exceed 20 degrees, and more precisely a wine should be kept between 12 and 14 degrees, and with a humidity of 70%. The method of storing wine is essential to preserve all its qualities and properties, and above all to not frustrate all the work done with passion to produce it, from harvesting the grapes to packaging.

Our advice is therefore to check, before proceeding to purchase, the placement of wines in supermarkets and wine shops, avoiding those placed on the shelves subjected to strong and direct light from spotlights and lamps, or even placed in the window and exposed for hours to Sun rays. Once you bring the bottles home, it is best to store them in the dark rather than in the living room cabinet. If you love to drink well, buy a refrigerator to keep your wines in perfect environmental conditions, and you will be able to consume them to the fullest of their characteristics and potential.

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