Did light destroy my beer in glass carboy?

[kman42]

I've had my first AG batch fermenting in a glass carboy for about 8 days in the house. I didn't think to cover it to protect it from light until today. It is not in direct sunlight or anything, but is exposed to normal ambient room light. Is this a huge problem? I just put a towel over it tonight.

kman

 

[Rick500]

It's probably okay, though it is best to cover it.

Incandescent lights are no problem, by the way.

 

[kman42]

It's just exposed to incandescents and then some indirect light through a couple of windows. It's looking good, so I hope this didn't inflict too much damage. Fermentation has slowed way down, but I can still see a few things moving around a bit; I haven't caught any bubbles in a few days though.

I'm doing a Stone Arrogant Bastard clone.

 

[Eigenmusic]

The higher the IBUs (therefore, concentration of alpha acids, which are the chemicals in the beer that go bad ith exposure to sunlight), the worse the damage. AB clones are up there in IBUs, but it doesn't sound like the light level caused too much harm; it is the bottle conditioning time that you have to worry about. Use brown bottles!

 

[mordantly]

its not uv that redoxes the hops. nearly all glass, especially home and vehicle blocks uv. so what the hell is it? radiation?

 

[Scimmia]

its not uv that redoxes the hops. nearly all glass, especially home and vehicle blocks uv. so what the hell is it? radiation?

Um, no, most glass does NOT block all UV radiation. It will usually block some, especially the in shorter wavelengths, but certainly not all. The reaction of iso-alpha acids and UV light is well documented, so making the claim that "its not uv that redoxes the hops" is a huge claim that would need some evidence to back it up.

 

[david_42]

Skunking is really obvious. It's a very fast process, so if the beer isn't skunked yet, no problem.

 

[shortyjacobs]

its not uv that redoxes the hops. nearly all glass, especially home and vehicle blocks uv. so what the hell is it? radiation?

lol, it's cosmic rays! Neutrinos even! Friggen tetryon particles be messin' with mah hops!

Glass doesn't block all UV, just some.

 

[Jumbo82]

Lighter beers are more prone to skunking than darker beers since light is better able to penetrate it. Arrogant Bastard is fairly dark, so I imagine it would take a while for even direct sunlight to skunk a full carboy of the stuff. You're fine.