Settle an argument!

Skunk, nasty, rotten, whatever name you give it, nasty SUN rotten wort is still ROTTEN by any other name. I've heard and seen all the arguments about hops and sunlight, temperature, etc. etc., etc. but I'm here to tell you that rotten beer ruined by sunlight is ruined beer. So what is the experienced opinion here? Have you had your wort exposed to sunlight? With non-exposed wort in the same room with the same ambient temps? I say sunlight ruins wort. The argument is that temperature ruins wort, not sunlight. I want experienced opinions to weigh in. If this has been done before (I'm sure it has) I apologize but search doesn't find it for me. Please weigh in ONLY if you have experience. :rockin:

Here you go:

This took 1 minute of googling "Beer and sunlight"

Photooxidation of isohumulones. End of argument.

Yep. And here's another one:

http://http://en.wikipedia.org/wiki/Beer_bottle#Lightstruck_beer

I may not have brewing experience, but I'm a master googler...

Yes final product the article addresses but I'm specifically asking for input on the fermentation stage and sunlight. Please, anyone who has experienced wort skunking while it tries to become beer respond. I've had to toss wort w/ yeast attempting to do its job skunk when exposed to sunlight. Not talking about the finished product. Has anyone experienced fermenting w/ exposure to sunlight?

The isohumulones are in the final product as well as the fermenting wort. I'm not sure what you're getting at or what difference you believe there are in the fermenting wort vs finished beer.

If they break down at any point you will have the rotten taste.

I've got other homebrewers agreeing with the links I've seen here about sunlight and "beer" (aka the finished product) but argue with me that sunlight ruins the yeasted wort (aka product in the works). I'm in agreement with Bert1097 about "or what difference you believe there are in the fermenting wort vs finished beer." when it comes to sunlight ruining it.

My whole argument is that 'yeast do it better in the dark' and I've gotten some arguments that I am wrong on that and sunlight will skunk a "beer" but not during the fermentation process. The discussion even went as far as how sunlight shining into a fermenter will raise the heat and the heat causes the "rot".

All I know for sure is I was fermenting in a glass carboy w/ a towel a few years ago. Mom visited, took the towel off, opened the kitchen door to the outside, and direct sunlight hit my corn/pale malt in the fermenter and rotted it in less than one day. Didn't notice the glass carboy being particularly warm either.

Since that time I ferment in a closet or a lagering tank and have not had a problem. The fellows arguing with me agree that sunlight skunks a beer but do not agree that it affects fermentation adversely. So the nice link to beer / sunlight articles do not build my case.

kontreren said:

My whole argument is that 'yeast do it better in the dark' and I've gotten some arguments that I am wrong on that and sunlight will skunk a "beer" but not during the fermentation process. The discussion even went as far as how sunlight shining into a fermenter will raise the heat and the heat causes the "rot".

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Yeast has nothing to do with it. I have made wine in direct sunlight, without any problems.
What skunks a beer is the UV radiation breaking down isohumulones that come from the HOPS, not the yeast. So, as long as you've already extracted the hops, your wort will skunk up if left in direct sunlight.

Inodora I have to respectifully disagree. Not about the isohumulones, I'm just now learning what that is. But about the HOPS not yeast. There were NO (zero, none, nunca, nada) HOPS put in the fermenting wort that rotted in less than one 8 hour day when exposed to sunlight. ... I am really hoping to find brewers who have experienced fermenting wort rotting by being exposed to sunlight to tell me their experience. ... Again, no hops were used so that argument simple does not hold water in this case.

why did you make a beer with no hops?

rycov said:

why did you make a beer with no hops?

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That'd be the $64K question...

Another one would be: did you use another bittering agent, like quinine bark, or dandelion? Maybe one of those has isohumulones as well...

rycov said:

why did you make a beer with no hops?

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To get past the hop skunking isohumulones side of this conversation.

Inodoro_Pereyra said:

That'd be the $64K question...

Another one would be: did you use another bittering agent, like quinine bark, or dandelion? Maybe one of those has isohumulones as well...

Click to expand...

Nothing unusual, just barley malt and flaked corn as mentioned in an earlier post.

Totally Irrelevant Sidebar: Beer w/ No Hops links (I guess the point is that it's been done):
http://ca.answers.yahoo.com/question/index?qid=20071220114534AAn8x7n
http://beermakers.tribe.net/thread/8e2c2b34-8119-41c8-8e21-14190372aa29
https://www.homebrewtalk.com/f12/very-low-hop-no-hop-beer-17599/
http://beeradvocate.com/forum/read/2201760

so this was a test? like to see if light would skunk an unhopped fermenting wort?

Sorry Kontreren, don't take it personally, but I'm gonna have to call BS on that.
In your original post, you said your wort skunked on you years ago, by accident.
Now, you say you brewed a specific, non hopped batch, with the only purpose of proving that isohumulones have nothing to do with the skunking process? Sorry again, I don't buy it.

All laboratory research points directly to isohumulones being the main cause of skunked beer. Now, there are examples of isohumulone-free beer (like MGD) still being photochemically active, but they don't produce the compounds that cause the skunky taste.

http://www.eurekalert.org/pub_releases/2001-10/uonc-ucf101701.php

Seems to me like you're looking for something that doesn't exist.

You need alcohol (and hops and UV light) for the skunking reaction. Sunlight does not skunk non-fermented wort, it skunks already fermented beer. Dark/opaque beers don't skunk (or do so only at a very reduced rate) because the light doesn't penetrate into the beer like it does a pale, clear beer.

im not trying to say that you're wrong. its just strange that you brewed a beer with no bittering agent. those links don't really say anything about this. yes it can be done. but most agree that it wouldnt be good. thats why i asked if this was meant to test just for this purpose. the fact that you said it was accidentally exposed, i guess means no. in other words it seems unlikely that your telling us what really happend. also it seems that you don't want to hear the answer you just want some one to say that you're right. if thats what you want then tell us. if not then i'd like to know a little more about this beer. and i hope im wrong, and im not trying to be a dick. i just don't see what your getting at really