Light Struck Beer

[Rod]

I tried an simple experiment to see what effect leaving my beer in grolsh bottle
in reflected sunlight would do to the flavour of the beer

This was after reading many posts which said that the green grolsh bottles would
make your beer taste bad , skunky was the term

My test brew was a Grumpy's Stella clone

The brew is now 21 weeks old

6 weeks ago I put 2 bottles at the window overlooking the verandah which faces the sun .

Put two bottles in the fridge

After two weeks tried one test bottle comparing it with the standard in the fridge , no difference

After 6 weeks , same test , same result no difference

small experiment , yes

but it would seem that the beer in my grolsh bottles , in this case , was not effected by the light

 

[Adamt]

Were there any actual hops used in the brew?

Or did the bittering/flavour come from a canned kit?

Canned kits usually contain iso-hop oils. Iso-hop oils are not affected by the sunlight, other things that are released by hops and stay in the beer are though. This is the reason Tooheys Extra Dry doesn't skunk, its loaded with iso-hop oils.

 

[Rod]

my notes do not include the variety of hops

the brew is a masterbrew ( prmium extract and grain brew requiring boiling ) from Grumpy's and I am sure there was dry hops pellets added to the boil maybe even two , one during and one at the end

ps should keep the instructions next time -- which will happen , these masterbrews from Grumpy's are superb.

 

[lonte]

I tried an simple experiment to see what effect leaving my beer in grolsh bottle
in reflected sunlight would do to the flavour of the beer

I've done similar experiment with clear bottles and a BOP Stella Clone. Only left in sun for 48 hours and then did a blind test side-by-side (after re-chilling). when the light-affected bottles were opened there was no mistaking them! Might try with green bottles next time i get a chance and see how it goes.

 

[barfridge]

I can taste the difference between the start and finish of a pint when I'm drinking it out in direct sunlight. Skunking definitely does happen, I've even had beers from bottleshop go bad when the fridges get sun during the day.

Great stuff doing the experiment, but I think you'll find iso-hops were used. Let us know if you try again with a properly hopped beer.

 

[warrenlw63]

Yep found the same thing as Barfridge.

Call me weird but sometimes I actually like the flavour/aroma of skunked beer. Not all the time. But when you're in the mood for it no probs. :blink:

Warren -

 

[Gough]

Yep found the same thing as Barfridge.

Call me weird but sometimes I actually like the flavour/aroma of skunked beer. Not all the time. But when you're in the mood for it no probs. :blink:

Warren -

You're weird Warren Although it at least gives Corona some flavour I guess... 'Skunked' beer is definitely a problem. Interesting experiment with your brew, but once smelt/tasted, skunked beer is never forgotten...

Shawn.

 

[warrenlw63]

You're weird Warren Although it at least gives Corona some flavour I guess... 'Skunked' beer is definitely a problem. Interesting experiment with your brew, but once smelt/tasted, skunked beer is never forgotten...

Shawn.

Just can't bring myself to tip it out... Never leave a fallen comrade behind.

Warren -

 

[Weizguy]

You're weird Warren Although it at least gives Corona some flavour I guess... 'Skunked' beer is definitely a problem. Interesting experiment with your brew, but once smelt/tasted, skunked beer is never forgotten...

Shawn.

I won't comment about your thoughts of Warren...apart from this mention.
Warren, I belive that some people believe that all Euro beer should taste like that. So, there may be a few people who like the skunk. <_<

Shawn, were U thinking of the skunked Kolsch from our BJCP exam?

Seth

 

[Gough]

I won't comment about your thoughts of Warren...apart from this mention.
Warren, I belive that some people believe that all Euro beer should taste like that. So, there may be a few people who like the skunk. <_<

Shawn, were U thinking of the skunked Kolsch from our BJCP exam?

Seth

Nah Les, I'm trying to block as much of that morning from my mind as possible... Funnily enough I've got less trouble forgetting the events of the night before...

You might have hit the nail on the head there though Les. Maybe a bit of extra skunk made it taste more like the green bottle Euro lagers from the bottlo fridge?

Shawn.

 

[drsmurto]

Sorry to burst your ballons boys but science has fixed the problem of beer skunking in bottles by adding chemcials to the glass manufactoring process. Hence the reason that lots of brewers, even the euro ones you lot seem love to hate can put there beers in clear and green glass. Yes, some isohop instead of using hops but the majority dont. Similar theory behind glass that blocks out UV light that we use in sungalsses, cars and even modern housing. Yes boys, science is our friend.

 

[Gough]

Sorry to burst your ballons boys but science has fixed the problem of beer skunking in bottles by adding chemcials to the glass manufactoring process. Hence the reason that lots of brewers, even the euro ones you lot seem love to hate can put there beers in clear and green glass. Yes, some isohop instead of using hops but the majority dont. Similar theory behind glass that blocks out UV light that we use in sungalsses, cars and even modern housing. Yes boys, science is our friend.

3 cheers for science!

 

[Gulf Brewery]

Sorry to burst your ballons boys but science has fixed the problem of beer skunking in bottles

Hi DrSmurto

You have my attention - do you have any links to info about this?


For those who don't think you can skunk beer, get some Hahn Light and leave it in bright sunlight for a while , it does get skunked. I did this for a few people doing the BJCP exam.


Cheers
Pedro

 

[paul]

Someone will have to ring Dr Carl on Thursday morning. He'll know and if he doesnt he wil find out for you.

 

[Kai]

I think it's too esoteric for Dr Karl to give a good specific answer.

 

[bugwan]

Here's an article or two on treated glass for beer:

The CSIRO has an article "Sunscreen for the amber fluid"

Some guy has a patent out on a process that removes Riboflavin from the brewing process using absorptive clay :excl: . Apparently Riboflavin is involved in the light-strike process

And some more info on skunking itself...

Quite an interesting subject, now that I've taken the time to research a bit. In normal practice, all of my beer is protected from light as a matter of necessity (I have a shed with no glass windows). It's good to know that any stale wafts in my brews are probably my fault!

 

[warrenlw63]

Warren, I belive that some people believe that all Euro beer should taste like that. So, there may be a few people who like the skunk. <_<

Nup. Not thinking for one minute that it ever tasted good in Heineken, Grolsch, Pilsner Urquell, Lowenbrau et al (though it probably added something to "unbore" Heineken). Just didn't mind it in the odd occasion in my own beers. I guess it was more a case of the flavours never became unpleasant enough to toss the glass in question.

Drink a bottle of LaChouffe for example. I've found quite a few instances of it containing some light strike. Strangely enough the beer can almost take on some added complexity as a consequence. OTOH I would never call LaChouffe an overly hoppy beer either.

Phil Markowski the author of Farmhouse Ales describes in his tasting notes of Saison Dupont as having a hint of a "light struck" character and not that unpleasant in the beer itself.

Food for thought. It's easy to understand why it's easily dismissed as an obvious fault in beer. That being said throwing every instance of a beer with it is like tossing out the baby with the bathwater. h34r:

Warren -

 

[drsmurto]

Hi DrSmurto

You have my attention - do you have any links to info about this?
For those who don't think you can skunk beer, get some Hahn Light and leave it in bright sunlight for a while , it does get skunked. I did this for a few people doing the BJCP exam.
Cheers
Pedro

Gulf, Hahn Light and beer used in the same breath......... not sure thats good science!

Bugwan, good link. Am a CSIRO man so was the info i was going to give! Plus, i work in the 'nano' sector and its amazing and sometimes a little disturbing to see how much nano-tech is already out there helping us but possibly harming us already and noone is told. Part of my job in the long term.......

I personally have the old pickaxe brown longnecks which are stored in a shed so light has never been an issue.

Would love to here what the wise man Dr Karl has to say on the topic tho, might email him on behalf of all of us.

So - if you have old pickaxe type brown bottles, its not an issue. If you are using kegs, obviously not an issue. Only becomes a problem if you are using stubbies from commercial brewers who arent using the new tech, not sure where you would get a list from. The coopers PET bottles are fine.

Cheers
DrSmurto