Lightstruck taste is a wine fault that can make wine hard to drink. Lightstruck taste can develop in some bottles, turning them into bad wine. What is more, you can make this taste appear right at home by doing a few tests, which is a great way to practise.
What is lightstruck taste in wine?
Lightstruck taste is a fault that develops in wine if it has been exposed to light too much. Gradually, the wine loses its aromatic richness and you end up with a bad taste close to garlic butter or cauliflower depending on the wine. This fault mainly affects white wines, sparkling wines and rosé wine. The tannins of red wine protect it more from this fault (which is not possible with the tannins of white wine, which are almost absent). You may also notice a slight discolouration of wine exposed to the sun.
How does lightstruck taste form?
Now that you know perfectly well what lightstruck taste is, it is interesting to understand how it forms and how quickly. By discovering these elements, you will be able to protect yourself from it more easily. Before going further, it is worth paying tribute to Alain Maujean, professor emeritus at the University of Reims-Champagne-Ardennes and author of the treatise on oenology, who discovered the origin of this taste.
The reaction behind this taste
Behind this taste is a chemical reaction between light and riboflavin (also called vitamin B2). Riboflavin is present in many foods but also in wine. The problem is that riboflavin reacts to light. More precisely, to wavelengths of 375 nm in the UV-A range and 446 nm in the visible range. These wavelengths are emitted, in particular, by sunlight and by a large part of fluorescent lights. In other words, there are elements in wine for which exposure to light triggers a chemical reaction. This chemical reaction causes the development of molecules with cabbage aromas and others with the smell of mothballs, acacia flower, or soap. Beyond the mere presence of light, this reaction is accelerated by temperatures above 20°C. So remember to keep these things in mind to store your wine well and when choosing your wine cellar.
How quickly does this taste form?
The speed of the reaction and of the appearance of this taste varies depending on many factors: container, contents, exposure, temperature, etc. That said, you can remember that lightstruck taste appears very quickly in a glass. A few minutes are enough to make your glass undrinkable. So, when you are preparing events or attending them, avoid having the champagne served too long before the buffet opens. In the bottle, lightstruck taste takes longer to appear. According to recent studies, you should reckon on between 15 days for clear bottles and 3 months for brown bottles. Of course, it also depends on the thickness of the bottle. In that sense, be wary when buying wine on the shelves of large supermarkets: they have been exposed to light for a long time and may therefore have largely developed this fault.
Protecting wine from lightstruck taste
Protecting against this fault is an everyday battle. It begins with the wine producer, who puts many measures in place. It must then continue at the home of the individual when storing their wine.
Protecting wine at production
The bad news is that we have not yet found a cure for this fault. So you really have to protect against it. To protect wine from this fault, there is a simple remedy: expose it to light as little as possible. So it all starts at production: you have to choose the right bottle. The point here is to find the right colour and the right thickness of bottle to block the light. Then, in particular where the wine is stored in clear bottles, covering the pallets with a black tarpaulin is a good idea. More occasionally, it is also worth wrapping the bottles in tissue paper, preferably dark. Finally, you have to choose the right lighting system. Until now, champagne houses opted for sodium lamps. These produce an amber light and were perfect for their use: they produce neither UV nor a bluish tint. That said, they are no longer manufactured from 2020. So professionals are now turning to LED units.
Protecting wine at home
You must protect wine from lightstruck taste in your wine cellar, in particular if you want to age the wine. A good solution is to turn to a wine ageing cellar. These generally have a completely opaque door. Some cellars can be glazed. You will then need to check that this glass protects against UV, to avoid your wine being disturbed during its rest.
Try the lightstruck-taste test
If you want to go further, you can do the test at home! For our part, we did it with Frédéric Zeimett, general manager of Leclerc Briant during our visit to the house. When opening a bottle of champagne, pour a small glass that will be used for this test. Then place it in the sun. Come back 10 to 15 minutes later and smell it. You will see very quickly that you do not want to drink it. You can of course taste it, but at your own risk.
And there you go, you now know all about lightstruck taste and how to protect yourself from it. To go further in learning wine, I advise you to join The Club. With The Club, you will get free access to exclusive content and will be able to learn wine easily.
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