skunky beer

[psorgatz]

I did an experiment with beer in green bottles, left a bottle of beck's out in light over night, one in light for a half hour, and kept one covered in the box. Within the half hour, you could already pick up skunky flavors, the one left out over night smelled like a cypress hill concert.

Also noticed that its not just sunlight that skunks beer, but artificial light will do it as well.

 

[ncbrewer]

I did an experiment with beer in green bottles, left a bottle of beck's out in light over night, one in light for a half hour, and kept one covered in the box. Within the half hour, you could already pick up skunky flavors, the one left out over night smelled like a cypress hill concert.

Also noticed that its not just sunlight that skunks beer, but artificial light will do it as well.

I read somewhere that fluorescent lights skunk beer but incandescent lights don't. What kind of lights did you use?

 

[yewtah-brewha]

I did an experiment with beer in green bottles, left a bottle of beck's out in light over night, one in light for a half hour, and kept one covered in the box. Within the half hour, you could already pick up skunky flavors, the one left out over night smelled like a cypress hill concert.

Also noticed that its not just sunlight that skunks beer, but artificial light will do it as well.

Im still tring to figure out the overnight thing, I didnt know that moonlight could skunk a beer!

 

[forstmeister]

I have noticed skunking of a good craft beer after only 15 minutes in the sun. I poured the can into a glass. Lesson here: drink canned beer from the can.

 

[dmashl]

Old comforters work too

 

[Red_Scooter]

[ame]http://youtu.be/_YhpauKGgQ4[/ame]

 

[stickboy46]

I just had a beer come out skunky about two months ago. It was horrible and completely undrinkable. I let it set in the keg for about a month before I tried it again. It got better, and now its at least drinkable. I won't serve it to any of my friends (except the one who likes hiny), but its still beer...

 

[schematix]

Surprising as it is it, it only takes a few minute exposed to direct sunlight to skunk a beer.

Try it for yourself. Buy yourself a 24oz can of Budweiser (or you're favorite lightly hopped macro brew) and pour it into a glass. Take a good sniff and note the lack of almost all aroma (specifically hop/skunk aroma). Leave it outside on a bright summer day for about 10 minutes and take a sniff again. Skunk!

 

[MorrisBrewingCo]

The fermenters sat on my tool bench in the garage were afternoon sunlight came in direct contact with them every day.

I see two problems:

1. Fermenters in garage means they were not climate control and you are fermenting at a fluctuating temperature.

2. Sun light contact everyday.

Solution:
Put your fermenters inside with a blow off valve (had a carboy explode in my closet) and wrap towels around it securing with a string,bungie,ziptie,etc.

 

[daggers_nz]

I've got 99 skunk problems but I can't figure out the source. Removed all my bottles from potential sunlight damage source, and it's not even consistent within a single batch - ie. the first few from this crate were great, but the one I'm having tonight is rank. Refrigerating seems to make it worse?!

 

[MorrisBrewingCo]

bottles

I don't bottle unless out of my keg to a growler for transportation because it takes too much time.

Could it be a sanitation or bottle filling process issue?

Or is it possible your brew is being exposed to oxygen at a point in your brewing process?

 

[daggers_nz]

Not sure. After a bit of reflection it seems to be only happening with amber-coloured beer - my Yooper's California Common, Caramel Amber, English Pale Ale, Irish Red.. My IPAs and pale ales/hybrids have been fine. There's no mutual grain, yeast or hop ingredient I can link them together with. I even bought some new bottles and sanitized them before using. Actually, I use a chlorine compound cleaner then thoroughly rinse.
I am seriously considering PayPal-ing someone a few dollars if they can figure out what my issue is. I don't have the room or money to keg my beer at this point.

 

[MorrisBrewingCo]

Try and not brew in the sunlight (includes fermenting or aging your bottles). Also, are your bottles possibly getting an improper cap seal or are you using a secondary with your amber colored beers?

 

[daggers_nz]

I have some curtains covering my fermenter room and where some of the crates live. The other crates are in a cupboard that receives no light. I downsized my bottle inventory when I thought a different stack were receiving sunlight but that has been mythbusted because my current affected batch was under where my fermenters live. I'm pretty sure my cap seals are fine too. Could it possibly be my water profile (I use hard tap water) not working well with crystal etc. malts?

 

[MorrisBrewingCo]

What temperature are you fermenting and aging your bottles?

 

[DrunkleJon]

Try and not brew in the sunlight (includes fermenting or aging your bottles). Also, are your bottles possibly getting an improper cap seal or are you using a secondary with your amber colored beers?

I previously asked about this one day while brewing outdoors in the sun this summer. I was told that beer will not skunk until after it has started fermenting. Found the thread https://www.homebrewtalk.com/f14/skunk-during-boil-416557/. here was the most helpful portion.

Quote:

The bittering agent generated from hops while boiling beer wort is a compound called isohumulone. Ultraviolet light can degrade isohumulone all by itself. But it turns out that visible light can also induce isohumulone degradation -- it just needs a helper molecule, in the form of riboflavin. Once the proverbial ball starts rolling (or, in this case, the electrons start hopping), a series of reactions take place that eventually produce the compound 3-methylbut-2-ene-1-thiol. That mouthful, known colloquially as 3-MBT, is your skunk. In fact, 3-MBT is chemically very similar to one of the three main compounds found in a skunk's defense spray.

The amount of riboflavin in malt is minimal, though it is present. It's mainly produced during yeast growth stages, if memory serves. Once that's in the wort in sufficient quantity, you run the risk of the reaction described above.

It seems like a decent enough source to me. Let me know if you want me to find something more authoritative, or something that speaks to riboflavin levels at different points during, or before, fermentation.

So as a result brewing in the sunlight probably isn't it.

 

[MorrisBrewingCo]

The fermenters sat on my tool bench in the garage where afternoon sunlight came in direct contact with them every day.

Try and not brew in the sunlight (includes fermenting or aging your bottles).

DrunkleJon, I included fermenting in the sun because that was most likely the initial causation. 10 minutes in the sun can cause skunk damage. If you brew in the sun, most likely you are wort chilling or letting the fermenter sit in the sun while you clean up. With all the the various things floating in the open air, I would suggest at least the post boil process of brewing needs to be inside.

 

[daggers_nz]

if I can't brew in the sun nor brew outdoors in the winter due to the weather I'm considerably f***ked.

 

[DrunkleJon]

I do not know how I missed the (includes fermenting or aging your bottles) part all 3 times I read the post. Sorry about that. I am not terribly worried about the cooling portion. I am sure when I build a cfc or get a plate chiller I will worry about it even less.

 

[Mead_head]

While my pot smoking days are done, I loved the smell of opening up a big bag of skunky weed. Personally this is what I associate the skunk smell of certain beers with and I love it. Has anyone done any experimenting to find the optimal uv exposure to maximize the skunky (big bag o weed) smell?

 

[roastquake]

While my pot smoking days are done, I loved the smell of opening up a big bag of skunky weed. Personally this is what I associate the skunk smell of certain beers with and I love it. Has anyone done any experimenting to find the optimal uv exposure to maximize the skunky (big bag o weed) smell?

To me, that's a different type of skunk smell. If you want it to smell like weed, use Centennial as your late hops, that's a dank hop