Thanks Greg,
The many compounds in wine will definitely absorb some wave lengths of light
specific to the compound. Polymerization or break down can occur.
Polyphenols can also break down due to UV light. There are hundreds of
compounds in wine. I would like to know what families are involved with
polymerization or break down due to light. Are the flavonoids involved and
are cinnamic acid family (phenolic compounds) involved? There are many more
non phenolic groups are they involved?
Eddie V.

"Greg Cook" > wrote in message
s.com...
> On 5/12/04 9:00 PM, in article
> , "Sabia Vanderzeeuw"
> > wrote:
>
> > Hi Greg,
> > Please explain why the wine should be kept in the dark. I have see this
item
> > in many home brewers (wine) books. There is no explanation of why. In
beer
> > there is the chemical change in the hop compounds due to UV light. Why
do
> > we, as wine makers always state that light is bad for wine. Is there a
> > scientific back ground? If there is please post it.
> > Thanks,
> > Eddie V.
> > The Wine And Beer Factory.
> >
>
> There are a lot of chemical reactions that are induced by absorption of
> light. Wine has many colored components in it - which means it's absorbing
> light at certain wavelengths. Light will degrade these. I'm not sure what
> kind of explanation you want. Light can induce polymerization of
polyphenols
> for example. The bottom line is, color and flavors can be harmed by light
> and wine will "age" faster in light than in the dark.
>
> --
> Greg Cook
> http://homepage.mac.com/gregcook/Wine
> http://homepage.mac.com/gregcook/aws
>
> (remove spamblocker from my email)
>