I know that sunlight can damage red wine. Is the same true for white wine? If so, why are so many whites and rosés bottled in clear glass?

Ask Dr Vinny

Hello there! I'm Dr. Vinifera, but you can call me Vinny. Ask me your toughest wine questions, from the fine points of etiquette to the science of winemaking. And don't worry, I'm no wine snob—you can also ask me those "dumb questions" you're too embarrased to ask your wine geek friends! I hope you find my answers educational, empowering and even amusing. And don't forget to check out my most asked questions and my full archives for all my Q&A classics.

Dear Dr. Vinny,

I know that sunlight can damage red wine, especially while it's fermenting in a carboy. Is the same true for Chardonnay or Pinot Grigio? I see a lot of white wines bottled in clear glass.

—Steve, Sparks, Nev.

Dear Steve,

It sounds like you’re experimenting with some home winemaking. Good for you! In general, it’s important to protect your wine from exposure to ultraviolet light. It’s particularly important when fermenting your wine in a clear glass carboy, because the light can harm the yeasts and interfere with your fermentation. Sunlight can also affect the temperature, and the yeasts can die if it gets too hot.

In addition to degradation and premature aging, sunlight can also cause wine to become “light struck,” a phenomenon more commonly associated with beer. A photochemical reaction forms hydrogen sulphide and mercaptans, which can cause skunky, cooked cabbage or struck-match notes. Whites, sparkling wines and rosés are more susceptible to getting light struck than reds, since red wines have more tannins, and tannins are known to be protective against this process.

Despite that, you're correct that many white wines and rosés are bottled in clear glass. There are two main reasons for that: tradition (which is very prevalent in wine packaging) and marketing (it’s appealing to see the color of the wine you’re thinking of buying, especially for rosé). These wines are made to be consumed when near-term, and best stored in a dark refrigerator or cellar until consumed.

Fortunately, most wine isn’t bottled in clear glass (the industry term for this clear glass is "flint"), and tinted glass filters most of those harmful UV wavelengths.

—Dr. Vinny

Collecting Storage Ask Dr. Vinny

More In Dr. Vinny

Do wine-preservation devices like Coravin actually work?

Wine Spectator's expert Dr. Vinny offers advice on using the Coravin and tips for other …

Jun 26, 2019

Which sparkling wines are made from Chardonnay?

Wine Spectator's expert Dr. Vinny offers clues for figuring out a sparkling wine's grape …

Jun 24, 2019

At what point of color saturation does a rosé become a red wine?

Wine Spectator's expert Dr. Vinny explains how rosés are made.

Jun 21, 2019

What kind of grape is Pouilly-Fumé?

Wine Spectator's expert Dr. Vinny explains the wines from this Loire Valley region.

Jun 19, 2019

Is it true that you can clean a red wine stain with white wine? What's the best way to clean a wine stain?

Wine Spectator's expert Dr. Vinny offers some tried and true methods and advice for …

Jun 17, 2019

How long will an unopened bottle of Champagne stay good?

Wine Spectator's expert Dr. Vinny explains how sparkling wine ages.

Jun 14, 2019




Restaurant Search

Restaurant Search