Plumpton College has, in partnership with Sparkling Wine World Championship (CSWWC) and Nyetimber introduced a ‘light strike’ awareness day coinciding with summer solstice - the longest day of the year.
The aim of the day was to bring the problem of light strike to everyone’s attention and to outline the steps that can be taken to prevent wine form being irreversible damaged, said Plumpton College.
While the topic of light strike (or Goût de Lumière), which occurs when ultraviolet and visible light react with the amino acids in the wine to transform them into unpleasant sulphide compounds, was well understood by Plumpton College graduates, the broader wine trade and general public remained oblivious to the problem, it said.
“Education about light strike is the key defence to this wine problem. There are many opportunities wineries, retailers and customers can take to reduce the damage to wine - it’s important to educate winemakers and those wanting to make a career in the wine industry about the issue,” said oenology lecturer Tony Milonowski.
Light strike taints, which can result in wine affected developing a taste reminiscent of dishwater, old potatoes, cardboard and cabbage when exposed to sunshine, can start to develop as soon as the wine bottle is removed from its cardboard box and is most common in still and sparkling rosé wines with many winemakers still chosing to showcase the pink colour of their wines through colourless glass.
“Clear glass is most commonly used for rosé and Blanc de Blancs styles. Producers always blame the marketing people for demanding clear glass bottles and whereas this might be true, it is a fundamentally a quality control issue, and for the sake of long-term reputation, no self-respecting producer should allow marketing to overrule quality control - they should switch to dark glass bottles, tick the box and move on,” said CSWWC founder Tom Stevenson.
Since starting to double-bag all clear glass bottles in his cellar in black plastic, the instance of faulty bottles had dropped by 94%, said Stevenson, who conducted the world’s first practical demonstration of growing light-struck aromas against unaffected samples of the same wine at the International Sparkling Wine Symposium in 2013.
English sparkling wine was ahead of the game, he said, with winemakers moving away from colourless and light coloured glass to darker green and brown bottles.
Passionate about light strike, English producer Nyetimber has been filling its wines into dark amber bottles since the 2009 vintage to protect against these exposures.
“Every year a lot of perfectly good wine is spoiled because it is stored in clear bottles and exposed to sunlight or the wrong type of indoor lighting. Once one learns to recognise the sulphury smell of a light affected bottle, you’ll be amazed at how prevalent it is in wines filled into transparent packaging,” said winemaker Brad Greatrix.
Trentodoc is also ahead of the game, but Champagne lags behind, according to Stevenson.