Flaws in wine : What is the taste of light ?

Fortunately, there are still solutions to avoid its occurrence. Thanks to this article, you will be able to understand how this defect appears and how to avoid it.

What is the taste of light ?

We often attribute the merit of the analysis of the taste of light to Alain Maujean with the publication in 1978 of "Knowledge of vines and wine". However, the first studies on the subject were carried out in a completely different universe : that of dairy products in 1971. Finally, it should be noted that this phenomenon is also known in the beer industry, although these three products do not develop this defect in the same way.

As I mentioned above, the wine subject to this defect will present unpleasant smells of cooked cauliflower and wet wool. It will definitely remind you the flaw of reduction And you are right ! The sulphur compounds come into play in these two phenomena. It is therefore quite normal that the latter can be confused since they produce a result quite close.

This defect develops over time when the wine is exposed to light.. Of course, the longer or the more intense the exposure, the more your wine will be impacted. Visually, your wine will lose its shine prematurely. At nose, the fruity notes will deteriorate and the wine will seem quite neutral to you. Then, they will give way to the famous unpleasant aromas announced above.

How the taste of light is formed ?

It doesn't take much for our phenomenon to be happy : some B2 vitamins, called riboflavin, as well as light and why not a little heat.

During the technical day carried by the Union of Champagne oenologists organized in 2016, a lot of technical data have been provided to take stock of this defect. Among those, riboflavin has been shown to be particularly sensitive to wavelengths 375 Nm in UV and 446 Nm in the visible.

Without going into detail and risking losing you, these wavelengths are emitted by sunlight, but also fluorescent tubes or even by the moon. Sensitive to these waves, this photosensitive vitamin will quickly become unstable. To try to find its initial state, she has fun transferring her energy to other molecules, such as nitrogenous and sulfur constituents. A riboflavin molecule is able to transmit its energy to up to 100,000 other molecules before being inactivated ! It is the disruption of the chemical structure of these nitrogenous and sulphurous constituents that results in the disgusting odors of cooked cauliflower and wet wool..

A high temperature will promote this phenomenon and will result in accelerating the process. This energy transfer, quite complex I grant you, will lead to a decrease in the color and astringency of the wine. For the time being, no viable solution has been found to prevent this deviation of the wine.

How long does it take for the taste of light to form ?

This phenomenon uses different parameters, so it is difficult to give a universal value to the appearance of this defect. It all depends on the temperature, the light and the amount of riboflavin in your bottle of wine. In your glass, wine can show this alteration after only a few minutes in the sun. For a bottle of wine, it may take only two to three weeks of light exposure to develop this defect.

How to protect your wine ?

On the winegrower's side, the choice of bottle plays an important role in combating this phenomenon. As I told you above, beers are also subject to this defect. For one as for the other, the color of the glass makes it possible to fight more or less effectively against this problem. It only takes two weeks in a transparent bottle to impact the wine, two months in a green bottle and three months in a brown bottle. You now understand the similar choices made by the wine and beer industries. Of course, the thickness of the glass also plays an important protective role.

On your side, a good wine conservation management is enough to protect your wine against the deterioration of the light taste. Obviously, it is essential to keep your wines protected from light. So, avoid keeping your bottles in a living room. Failing that, you can put them in the room least exposed to natural light and use a LED lamp in this place.

Finally, if you are thinking of buying an electric cellar, choose it with a solid door rather than glass – i see you coming, UV glass does not guarantee you to completely avoid the problem -.

It is not uncommon for Blanc de Blancs Champagne bottles to be transparent. I invite you to leave these bottles in their protection, whether it is a box or a colored plastic. If it's not the case, wrap your bottles with an ideally black or silver foil. Orange or red cellophane also works great and is often used by winegrowers.

Thank you retailers...

With abandoned bottles in full light on the shelves of your favorite shopping center and with transparent bottles to let the wine dress clearly visible, it is not uncommon today to come across this flaw.