light struck

koopdavisj · 01-02-2006, 03:50 AM

i did a search, but cannot find the stage in the brewing process that light exposure begins to skunk your beer. should i take precautions from the pont of pitching my yeast or not worry about it until later on?

Genghis77 · 01-02-2006, 04:38 AM

I believe the problem is mainly associated with storage either outside or under prolonged exposure to flourescent lights. But if using carboys you might want to put a blanket over it. I haven't found it a problem on home brews, and only rarely with store bought beer. But weather here isn't rated as the sunniest.

rewster451 · 01-02-2006, 04:55 AM

I agree with that. I always keep my carboys in closets, and my bottles behind my couch with a blanket over them. As long as you don't leave your carboys outside, or right in front of a window, I don't see it being a problem.

brackbrew · 01-02-2006, 05:01 AM

I agree with rewster and genghis...I always put a dark t-shirt over my carboy during fermentation. If you don't have a satisfactory way to control the temperature of your fermentation, you can also put it in a rubbermaid tub of cool to cold tap water..especially if you want to ferment at the lower end of a yeasts temperature range for less attenuation.

usmcruz · 01-02-2006, 07:45 AM

Quote:

Originally Posted by koopdavisj

i did a search, but cannot find the stage in the brewing process that light exposure begins to skunk your beer. should i take precautions from the pont of pitching my yeast or not worry about it until later on?

As soon as your wort begins to ferment it is susceptable to being light struck. In as little as a 3 minute exposure to light can lend a skunky flavor to your beer. hope this helps

**Denny's Evil Concoctions** · 01-02-2006, 08:21 AM

Like usmcruz said. It's the interaction of UV with the hop oils that skunk beer. Incadecent lights should be ok. Flourecents and sunlight BAD. Blacklights as bad as sun, so don't leave your carboys at the strip club or a rave.

Sunlight can skunk beer fairly fast, most flourecents take longer. Depends on the spectrum the Flouro puts out.

I'm guessing those "daylight" colored ones would be worse since they are around 5600 deg Kelvin. The avg being about 4000K, (an incadecent is usually at 3200K.) Flouro's put out some light out in the UV scale even if they are 3200K.

http://www.cameraguild.com/technology/kelvin.htm

**david_42** · 01-02-2006, 02:47 PM

Once the hop oils convert in the boil, the danger period starts. According to the guys at OSU, beer can skunk in 15 minutes in the sun and the higher the hops the faster it will happen.

Most commercial beers are in brown bottles so they don't have much of a problem. Most homebrews aren't around very long. No problem!

casebrew · 01-03-2006, 06:12 PM

15 minutes of direct sun, if in clear bottles. I'd guess that the depth of a carboy helps prevent skunking. And, it is not the UV, it is the visible light near the blue/green range. Heinekin in green bottles is skunky on purpose- they think american drinkers like it that way. Corona is in clear botles, but they reccommend drinking from the bottle so you don't inhale too much skunk, and sticking a lime into the bottle hides the arome even better. Hmmm, I wonder if dark beer is less skunkable, the dark won't let light in very far?

**DeRoux's Broux** · 01-03-2006, 06:17 PM

yep, pretty much anytime after hops are added, you have potential for skunky brew if exposed to light. according to web-search, some of the Mexican breweries actually have a machine they run cans through to give it the skunk flavor, like the bottles. i know Papazian says to set the beer in sun light for 15 minutes for the "authentic" cerveza skunk. no thanks!

homebrewer_99 · 01-03-2006, 06:22 PM

No skunks here!

I use a dark T- or sweat shirt over my carboys.