How to defeat oxidation?

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brett

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While I still consider myself new to homebrewing, I have identified and knocked out all off-flavors I have encountered. That is, except for one. A "cardboard" aroma and taste in my session ale, most likely caused by oxidation.

It comes out in that brew, I think, mostly because it's a more delicate, neutral style of beer, and thus less forgiving of off-flavors. Any off-flavor is detectable. I defeated the "fresh cut apple" taste by fermenting at lower temperatures and conditioning longer, but I still have a faint cardboard taste and aroma (more aroma than taste).

I feel pretty confident about my siphoning abilities. I'm thinking it could be Hot Side Aeration, but I'm not sure... after the boil and cooling down, I rack into my carboy fermenter @ ~80F. I then shake the cooled wort to aerate. Is this where my problem is? Should I be more patient and let it cool down to below 75F before aerating?

Have any of you had the cardboard problem? If so, what did you do to overcome it?
 
Now I'm no expert, but from what I know about hot side aeration (which is relatively little I must admit), I doubt that a difference in 5F would make any difference at all, and that is assuming that you would be able to create enough oxidation to get off flavours just from shaking it. I've got to say that I'm a bit sceptical about the whole theory of hot side aeration - but more so, I don't think that at the homebrewing scale it would be really possible to create much oxidation from just shaking when the wort is hot. If it is hot side aeration, I hear that it becomes more prominent as the beer ages, so have you noticed this happening? If so then maybe that is the problem.

I'm assuming you rack to a secondary, and you say you trust your siphoning, but do you purge the fermentor with CO2? It sounds to me that you'd be doing that already though.

I gotta say that I've never really noticed a carboardy taste in my beers, but then again I'm still at the kit + partial stage due to lack of funds and space - another story entirely I know.
 
If you really are racking carefully, my best bet for you is in your bottling technique. I use a bottling wand on the spigot of my bottling bucket. If I push the bottle fully up right away, the beer splashes around in the bottom of the bottle quite a bit. If I bring it up slowly, the beer fills the bottom of the bottle more slowly. Then I can push it all the way up and finish filling. BTW do you taste when you rack? If so when does the cardboard taste/smell start?
 
If you brew in a vacuum there is no risk of oxidation......ok sorry JJK. Just rack carefully and make sure you limit the exposure and you should be golden
 
How long does it take to notice the effects of oxidation? I kegged a honey ale a while ago and when I first tapped it, the cascade hops were clearly evident. Not the hops are less noticable and I think I detect a slight cardboard taste. Is this oxidation finally coming through or just a progression whatever the beer has been wanting to do?
 
brett said:
I bottle exclusively.

I had a thread not too long ago where I discussed the effect of letting a bit of air into the line while I was bottling the last few bottles of a batch. I noticed that the bottling wand was especially effective at introducing the air into solution. All I did was allow some air to enter the line when the level was low in the bottling bucket.

It was pretty astounding how dramatic the effect was on the bottles in question after several weeks...there was no mistaking the off-aroma and horrid flavor caused by the oxidation.
 
It's not HSA. That just isn't going to happen at 80°F. It sounds more like a post-fermentation oxidation problem, and I agree that it's probably at bottling.

I never liked the bottling wand that I had because it didn't give me much control over the process. Instead, I just used the old snap clamp thingy. I would place it just far enough up on the hose to let me lower the hose to the bottom of the bottle and still comfortably operate the clamp. Open the clamp, fill the bottle, close the clamp. No splashing. The hose would displace just enough beer that I would have a good headspace in the bottle after removing the hose.

Keep that headspace down, too. There's oxygen in there. You aren't filling Bud bottles, so you don't need that fill to be so far down the neck. A half-inch of headspace is plenty for homebrew. If someone says something about a "high fill," educate them.


TL
 
Hmm. Ok, here's the situation. Some bottles have the cardboard taste while others from the same batch do not.

Now, I'm thinking it's most likely something at the bottling stage. I always taste at bottling time and the oxidation isn't a problem then. I think the caps I use are oxygen absorbing... I'll have to double-check that though.

Thanks for the tip on the bottle-filler wand. Now that I think about it, there could have been a lot of bottles that had significant air bubbles going through them at bottling, especially those last few bottles, when I have to tip the bottling bucket.

The next batch I make, I will take a lot more caution when bottling, specifically avoiding any and all splashing due to filling the bottles too fast. I will also purposely fill some bottles quickly, set them aside, and compare.
 
It's a little bit more involved, but I always bottle with Kraeusen (actively fermenting beer) now. Since the yeast is fully awake and active it will consume any O2 that gets into the beer at bottling time.

I may have to give it the ultimate test and stick the O2 wand in a few bottles next time I bottle.

Kai
 
If it is a bottling problem and you experience it in only some of your bottles, then do as I do when bottling.

I fill to normal levels ( 1 inch space ) and place the cap on the bottle and set it aside until all my bottles are filled. The time spent filling the bottles allow for some O2 to be expelled due to the primeing sugar mix reacting with the beer causing a CO2 buildup. You'll actually hear the caps bouncing on the bottle lids as the O2 is being expelled.

All you do then is to start capping as usual starting with the one you filled first. I have never had O2 problems in bottled brews and my brews sit for a long while in bottle before being drank.
 
Kaiser said:
It's a little bit more involved, but I always bottle with Kraeusen (actively fermenting beer) now. Since the yeast is fully awake and active it will consume any O2 that gets into the beer at bottling time.

I may have to give it the ultimate test and stick the O2 wand in a few bottles next time I bottle.

Kai

Hello Kaiser,
Do you run the risk of bottle bombs using this technique?
Thanks,
Chris
 
Chris_Dog said:
Hello Kaiser,
Do you run the risk of bottle bombs using this technique?
Thanks,
Chris

No, since I calculate the amount of Kraeusen to be added. It's a little more complicated then just weighing sugar, but it has the same effect of getting a predetermined amount of fermentable extract into the beer.

Kai
 
Ive noticed on my last batch that there was foam in the bottle as i was bottlling.Couldnt the foam push out the oxygen? Damn I hope my beer isnt ruined.Can anyone here reccommend a better type of botlling wand that wont make the beer bubble?




Sean
 
MMMIPA said:
Ive noticed on my last batch that there was foam in the bottle as i was bottlling.Couldnt the foam push out the oxygen? Damn I hope my beer isnt ruined.Can anyone here reccommend a better type of botlling wand that wont make the beer bubble?
Sean


As long as you were not introducing air into the line with the beer @ the spigot mouth, no worries.


Bubbles in the line do not necess indicate that you introduced air.
 
brewt00l said:
As long as you were not introducing air into the line with the beer @ the spigot mouth, no worries.


Bubbles in the line do not necess indicate that you introduced air.

Thanks for reassuring me :mug: I may have a bottle or two that are oxidized then due to being the lasr of the batch and may have gotten some air in them.Oh well two are better then 48 :rockin:




Sean
 
boo boo said:
If it is a bottling problem and you experience it in only some of your bottles, then do as I do when bottling.

I fill to normal levels ( 1 inch space ) and place the cap on the bottle and set it aside until all my bottles are filled. The time spent filling the bottles allow for some O2 to be expelled due to the primeing sugar mix reacting with the beer causing a CO2 buildup. You'll actually hear the caps bouncing on the bottle lids as the O2 is being expelled.

All you do then is to start capping as usual starting with the one you filled first. I have never had O2 problems in bottled brews and my brews sit for a long while in bottle before being drank.

You know, I've done that before, and I've even had the bottle caps fall off due to released CO2... It's a good method though. I'll make sure to do that from now on.

Most problems come down to something simple and stupid anyways. I expect this one is no different. I'm bottling this weekend, so we'll see how these methods work out.
 
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