From the HBD Archive
Subject: UV and Skunky
Date: 1989-01-28 00:36:46 GMT

In Homebrew Digest #59, Al Korzonas inquired:

[ I believe that it's UV that causes anything to oxidize
faster. I felt more safe using brown bottles because
brown seems to be further away from the violet end of
the spectrum than green and because the brown bottles
are darker. On the other hand, doesn't UV have a hard
time getting through regular glass and UV lights are
made of quartz (or something like that)?

Am I fostering a valid concern or is the difference
so small as to be negligible?]

The absorption coefficient of bottle glass in the UV is infinity for
all practical purposes. However, it is my understanding that the more
energetic visible colors can interact with hops extract to produce the
skunky flavor. These colors can penetrate clear and green bottles.
This is particularly noticeable in beers bottled in green bottles that
have been sitting in grocery store coolers that have fluorescent

I bottle in long-necks of all colors and store the bottles in their
original boxes in rooms that are usually dark. The bottles are
plentiful here in Oregon where we have a bottle deposit law. I have
never had a skunky tasting batch.

On the subject of clear plastic bottles, a friend has bottled ale in
these, and apparently he hasn't had any casualties. However, I would
discourage the use of plastic in bottling, due to the possible leaching
properties of beer. Also, plastic bottles are not very attractive, and
this is not in keeping with the spirit of home brewing as I envision

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