the light and hops question

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fischfam

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I have a recent batch of Dark Chocolate Stout in my primary for 1.5 weeks in which this time I am using a 5 gallon glass carboy. Someone was over yesterday and told me that if I have hops in anything that light gets to it will make it skunk. (I knew about green glass and skunk but never thought about it while fermenting). Now this is sitting in my living room not in direct sunlight but rather just indirect light. I have then since covered it with a brown paper bag but I was just wondering how detrimental and quickly light will effect beer in beer in a clear glass primary fermenter. Needless to say I will most likely use my white fermenting bucket next time.

Thanks!
 
fischfam said:
I have a recent batch of Dark Chocolate Stout in my primary for 1.5 weeks in which this time I am using a 5 gallon glass carboy. Someone was over yesterday and told me that if I have hops in anything that light gets to it will make it skunk. (I knew about green glass and skunk but never thought about it while fermenting). Now this is sitting in my living room not in direct sunlight but rather just indirect light. I have then since covered it with a brown paper bag but I was just wondering how detrimental and quickly light will effect beer in beer in a clear glass primary fermenter. Needless to say I will most likely use my white fermenting bucket next time.

Thanks!
Click to expand...

It might be fine. Just throwing a towel over a fermenter or a t-shirt or something is enough to protect it. You don't need much direct light to skunk a beer, but I'm not sure how indirect your light is nor how bright so it would be just a guess to say if your beer is affected.
 
I use a BB ale pail & a Cooper's micro brew FV's,& cover them both. Better safe than sorry. Depending on what you cover it with,I think it helps stabilize temps a bit too. It's been rather cool in here,& the velvet smoking jacket I covered the micro brew FV with is staying at 22C,or 71.6F.
 
After fermentation has taken place, the compounds in hops are susceptible to being modified by the sunlight into the same compounds in skunk spray. And they have an incredibly small threshold of perception by humans.

Direct sunlight can skunk up a glass of beer in like 10-15 minutes (I've done this). Darker beer is less susceptible simply because the light waves are somewhat filtered by the beer itself.

Cover that carboy up ASAP and remember for next time. I used to put the box that the carboy came in over top of it leaving the airlock sticking out. I've also used paper bags and even T shirts.

Just make sure to block the sunlight.
 
thanks and it's covered now. I guess that i will be able to tell if it's skunked during bottling if i taste it?
 
I just stumbled over this thread, I have a Lager that is in primary at this time and in the basement where indirect light is on (a light bulb). I'm assuming that a florescent light won't affect the wort while in primary, by the thread's progression of information. I would like to say that also, i have made several "spirits," as well in direct sunlight and have not been affected.
 
It is compounds in the hops that are effected by the light. If you didn't use hops, you shouldn't have a problem with light.
 
Fluorescent lighting is the one to watch out for. If it's only a mild amount it might take a while, and if you are fermenting it in a bucket you have better protection.

Direct sunlight is WAY more powerful than a small amount of fluorescent light. I really can't say how long it would take to make it noticeably skunky.

The best bet is to take a sample and taste it. It's not going to get better if it's already skunky.
 
I just transferred it to a secondary fermenter and there was no taste of skunk at all. I guess indirect light has little effect on hops since this was in a clear carboy for 1.5 weeks in my living room. No direct sunlight light, but rather ambient light from windows (indirect sunlight) and general household lighting.
 
Quick follow up question:

Do the hops react with UV light or visible light? Or both? If I periodically use a flashlight to check up on fermentation, is there any danger in skunking up the beer (it's otherwise covered and in a dark cabinet)?
 
TCGoose said:
Quick follow up question:

Do the hops react with UV light or visible light? Or both? If I periodically use a flashlight to check up on fermentation, is there any danger in skunking up the beer (it's otherwise covered and in a dark cabinet)?
Click to expand...

Hops react to both but react to UV light much much quicker.
 

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