I generally like to let my fermented beer sit in the primary fermenter for a couple of hours in the kitchen (where I bottle) to give any sediment a chance to settle to the bottom of the carboy. I haven't had any issues with skunk beer, but am I testing fate by doing this? I don't have blinds in my kitchen. The sunlight this time of year in my region is mild at this time of the day (17:00 EDT) and it's not in direct sunlight. More like a shaded section of my kitchen.

  • 1
    Do you have fluorescent bulbs in your kitchen? I believe (not positive) that these types of lights can skunk beer as well.
    – GHP
    Sep 26, 2012 at 16:02
  • I do, but I actually turn them off (partially for this very reason).
    – senfo
    Sep 28, 2012 at 17:51

2 Answers 2


Your beer will be fine for a few hours in the kitchen.

Skunking is caused by the ultraviolet radiation which provides energy for reactions involving the isomerized hop acids and sulphur compounds in the beer. While there is a small amount of UV radiation emitted by fluorescent bulbs, it's much less than sunlight - 8 hours under a fluorescent bulb is about the same as a minute of sunlight - about 1/500th the amount.

It takes a few minutes of sunlight to skunk a beer, so you'd need to leave the beer under the fluorescent lamp for 24 hours or more, and if your fermentor is semi-opaque plastic bucket it will provide some UV protection, so even longer would be needed.


If it's not direct sunlight, the reaction that produces skunking will take longer, but you're not completely safe. You should probably take steps to limit the amount of light as much as possible in that situation. Maybe throw a towel over it as it sits.

  • I assumed it would take many days or weeks under fluorescent bulbs or daylight to cause skunking. Do you think there's any risk at all for just a few hours? Especially when stored in bulk like a fermenter, where there is less surface area?
    – Hank
    Sep 26, 2012 at 23:10
  • 4
    All I can tell you is that I've had very hoppy beer in a pint glass skunk in less than 5 min. in direct sunlight. That's not exactly analogous to your situation, but it's enough to make me careful about exposure to sunlight.
    – Denny Conn
    Sep 28, 2012 at 15:45
  • Interesting. I guess I should be more concerned about it. Maybe I should do a test with bottles left outside and see how many days it takes until there's a taste difference.
    – Hank
    Sep 29, 2012 at 17:27
  • I've found an old t-shirt works well to cover a carboy with. Jan 29, 2014 at 3:53

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