Finding faults: light strike


Illustration: Nicolas Boron
In the latest instalment of our series looking at wine faults, we look at how light can damage wine

Ever wondered why Cristal’s clear glass bottles come wrapped in orange plastic? This fault is the simple answer.

Light can cause the production of volatile sulphur compounds in a wine, giving it aromas of cooked cabbage or onion – a fault described as light strike. It doesn’t take long for it to take effect, either – some suggest as little as half an hour in direct sunlight can mar the wine.

It’s only certain wavelengths that are damaging, so can be easily prevented by bottling wine in dark glass (and the thicker the better, too), or using protective wrapping (à la Cristal).

It’s a particular problem for sparkling wines or rosé, the latter of which is rarely bottled in coloured glass.

For wines in clear glass bottles, it is avoidable: they just need to be kept in the dark (or shielded from light) as much as possible to avoid being “light-struck”.

Read the rest of our series on wine faults here.