Exposure of white wine to light results in a photochemical process that spoils wine, according to a research conducted at the National Wine and Grape Industry Centre (NWGIC) at Charles Sturt University (CSU), New South Wales.

Wines are usually exposed to light after bottling and during storage as they are stored for longer periods and such exposure could spoil and reduce its shelf life.

To study the effect, NWGIC along with Dr Daniel Dias of The University of Melbourne conducted a research under which they examined the impact of different wavelength lights on the wines stored in different coloured bottles.

Lead researcher Dr Andrew Clark told phys.org that they conducted a series of experiments to understand the impact of light on different white wine components such as tartaric acid and iron, and found that a chemical process called iron (III) tartrate photochemistry affected white wine by consuming its preservatives and changing colour to brown.

"Darker coloured wine bottles with a thicker wall of glass were found to offer increased protection from this photochemical process. These darker and thicker bottles absorb more light so less reaches the wine and the extent of detrimental iron(III) tartrate photochemistry is limited," he added.

"The darker green and amber coloured bottles were particularly useful to absorb the active wavelengths of incident light."

CSU PhD student Paris Grant-Preece is further carrying out experiments at NWGIC to study the impact of light exposure on wine.