Ultraviolet disinfection of Beer

[johnnymax]

I saw a post from a brewery in my state which made me believe they use Ultraviolet disinfection of their beer when bottling.
I have always understood that UV light would skunk a beer.
I have seen many Ultraviolet disinfection units for sale for use with beer.
Does anybody have any experience with this technology with beer?

[AnthonyB]

Would have to see the post in question but I would guess they were referring to treating bottle rinse water with ultraviolet versus treating the beer itself.

[johnnymax]

Would have to see the post in question but I would guess they were referring to treating bottle rinse water with ultraviolet versus treating the beer itself.

That makes sense....

[dick murton]

Definitely only use UV on water.

I wonder if you could use UV on beers only brewed with stabilised hops? - the sort used in beer for clear glass. Hmm. Now there's a thought instead of pasteurisation / sterile filtration. (only joking)

[PolarisBrewing]

I was under the impression that stabilized hops only existed in CO2 extract? Does the compound that cause skunking only come out in longer hop boil times?

[dick murton]

I'm sure I have the chemical reactions etc somewhere, but I am not a biochemist, and have not bothered to find out exactly why stabilised hop compounds remain more stable. The stabilised extracts I am aware of are stabilised with magnesium, presumably to replace some of the hydrogen ions in the iso alpha acid. They must therefore be more stable in the presence of UV light and not turn into smelly / different tasting compounds, giving so called skunky flavours / smells.

The length of the boil doesn't make non stabilised iso alpha compounds more, or less prone to "skunky" characteristics.

And you are right that the alpha acids have to be extracted, and then stabilised, so are only available as "manufactured" hop products.