You are not likely to find facts about beer on a web page about goat-farming, now are you?
I’ve been brewing for over 20 years, and in that time I have conducted countless beer-judge training sessions. One of the standard tricks is to skunk some beer by leaving it on the dashboard of a car for an hour or so. This gives you a beer to teach people with. 
Read the pages carefully. They point out that light is bad. Period. Yes, UV gets a bad rap, but it is the blue that causes the damage.
Ah. Ignorance duly fought. Thanks.
For good measure…
You know, even though wine isn’t beer you should not bottle your reds in clear glass.
It won’t go skunky but the color will be “stolen”.
Something else I just stumbled across that may be closer than my rapid turn over theory.
*“How do some beer makers get by with using clear bottles? There are a couple of approaches. First, you can chemically modify the beer during production to remove the components that react with light. No reactants, no skunky beer, no matter how much light you have.”
That’s what Miller does. They chemically alter their hops.
I’m tempted to say that real brewers don’t, but there is no arguing with a brewery that large. It’s moose piss, but it’s consistant moose piss.
Moose piss, that’s insulting to Moose Piss. Miller’s is just dirty beer-like water.
It is to beer what Kraft[sup]TM[/sup] individual slices of Cheese Product[sup]TM[/sup] are to Good Aged Cheddar.
I don’t really know much about beer bottles, other than Sierra Nevada’s, which I seem to be becoming an expert on. 
I do know more than I ever expected to about wine bottles, however.
First, clear glass is called ‘flint’ in the industry. Brown is ‘amber.’ (Sorry, it was driving me crazy) 
If the beer packaging industry is anything like the wine packaging, there are probably 5 or 6 different ambers. (Light Amber, Dark Amber, etc., who knows.)
To answer Case Sensitive’s question, some wine does come in amber bottles. OK, actually I can only think of one varietal, Gewurztraminer, but still.
Just from reading this thread and a few of the linked pages, I’m personally coming to my own conclusion, which is a mixture of the 2 main reasons given.
The UV light affecting the beer, and marketing.
I’m basing it on my knowledge of wine bottles. Like John F said, reds aren’t bottled in Flint, they’re bottled in different shades of green (Antique Green or Champagne Green usually, both fairly dark.) But whites are, like Sauv Blanc or Pinot Grigio in Flint or Chard in Dead Leaf Green (a light, almost yellow color.) (Pinot Noir and Syrah are usually in DLG as well.)
There are definitely chemical reasons why reds are in dark glass and whites are in light, and it was obviously discovered centuries ago. So, even though times may have changed, and we are able to preserve the product better through, I don’t know really, better transport and/or storage, whatever, or if the finished product never sits on a shelf long enough to be noticably altered by exposure to UV light, consumers expect to find that certain style of wine (and maybe beer?) in that certain style and color package.
I’ve noticed in this thread that examples of beer in flint or green tend to be lighter styles, lager/pilsner, etc., while the darker ales and stouts are in darker (amber) bottles. Perhaps the Germans/Czechs/etc. found the green glass preserved their product better, and found it more appealing than another color (like amber), or perhaps it wascheaper or more readily available then*, and so began the great green glass trend.
*If, for example, many of the large breweries started noticing the green glass=better tasting beer after transport, the longer runs at the glass house would be economical to the smaller breweries, since changing color for a smaller run would increase the cost.
The same reasons now, that you’ll generally find certain wine varietals in certain wine bottle shapes (and color, to a small degree) . Although this is certainly not a hard and fast rule, you’ll tend to find the varietals made famous by the Bordeaux region in France in Bordeaux (Claret) bottles - Cabernet Sauvignon, Sauvignon Blanc, Merlot, etc. And you’ll find those made popular in the Burgundy region in Burgundy bottles - Chardonnay, Pinot Noir, etc. Same for the Alsace region (Hock bottles), and Champagne.
Anyway, just my WAG. Time for me tro drain another amber bottle.
Didn’t anybody read my original query? I was asking about visible light vs. UV being the actual culprit.
Neurotik’s post is also “interesting”. The first link requires a password. The second link was selectively quoted. First of all, so UV causes breakdown products in the lab. And??? That doesn’t mean in the slightest bit that ordinary UV gets inside beer bottles in sufficient bottles to be a problem! UV can destroy a lot of organic stuff. But the issue remains, is it a problem in this situation? If you read the article further you see this:
“Loading the reaction mixtures into transparent syringes and exposing them to visible light at the same time as they were injected into the ionisation source of a quadrupole time-of-flight mass spectrometer gave the team a real-time analysis technique. Photooxidation of isohumulones by excited beer flavins lead to the lightstruck flavour in beer.” (Emph. mine)
Which I am also not impressed by. Are they talking clear plastic syringes? How much light? Etc. I don’t think this proves anything about visible light either.
Putting a beer on a dashboard and finding it goes funky proves nothing about what part of the EM spectrum actually caused it to go bad.
Nothing.
It’s an anecdote, not Science. silenus presumably didn’t measure the amount of UV, visible or IR getting into the bottle. What’s more, with the extra layer of car glass, you can pretty much rule out UV entirely.
And, seriously, I would trust a goat-farming site more. When you get into a world dominated by faux-connoisseurs, you know you gotta be very selective in who you trust.
ftg,
I think way back when you insinuated that hops don’t improve the taste of beer people wrote you off as a goof.
Then you question the tons of links added some goofiness.
It could all just be a misunderstanding. I think you should send an email to the guy from my link for some of his laboratory data he might share…
Richard Hartel is a professor of food engineering in the department of food science at UW-Madison. He teaches courses on food processing and food engineering and researches the chemical and physical changes that take place during manufacture and storage of foods. For more information about the field of food science, contact the UW-Madison department of food science, www.wisc.edu/foodsci.
“The skunky odor in beer comes from the same source of chemicals, regardless of whether it’s a Sam Adams or a Red Stripe. A class of chemicals called isohumulones, found in the hops, is converted to a thiol by the action of ultraviolet light. The reaction, involving generation of very short-lived and very reactive compounds called free radicals, is caused by the action of ultraviolet light on the isohumulones.”
If that does not convince you then you should start to embrace the thought that perhaps nothing can.
This dude is a freaking food engineer that studies chemical and physical changes. He is telling us what happens to the beer… :eek: And a multitude of brewers have written articles as well home brewers with decades of first hand experience. …think about it that’s all I’m sayin.