Help me find my oxdiation issue!

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Gremlyn

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After reading my score sheets from the HBT competiton, one thing is apparent to me...I have an oxidation issue! 5 of the 6 score sheets I got back dinged me for oxidation (thats with 3 different brews). I submitted an ESB, Irish Red, and a Dunkelweizen; these three beers were brewed specifically for the competition and had sat a total of about 2 months total before being judged (only 1/2 of that time in the bottles). I thought it took a lot of oxygen to cause a noticeable problem, and I don't think that much is getting in for me, but obviously it is somewhere. Here is as in depth a run down of my brewing process as I can manage to give:

1. I do 5 gallon batches, full boil on my electric stove top with the help of a single heat stick. My kettle is an 8 gal Megapot with a bargain fittings weldless valve and sight glass.
2. I batch sparge, usually two equal sized batches at ~180-185F.
3. To transfer my wort to the boil kettle, I just open up the valve on my MLT (5 gal Rubbermaid with brass ball valve) and let it flow, after vorlaufing of course. It probably flows in from a height of 18" at most, obviously the height reduces as the kettle fills. The does cause a lot of splashing.
4. I boil generally for 60 mins, though I am now thinking of going for 90 after my Irish Red was dinged for DMS.
5. I cool the wort with my 25 ft 1/2" IC, usually down to 80-85F in about 20-30 mins. Once there, I transfer to my plastic bucket fermenter. I was doing this with a short piece of tubing that helped to aim the wort into the bucket but have since gotten a longer piece of tubing that actually rests in the bucket to minimise splashing (because it would make a mess). I take my spoon and give it a good sloshing around to get some air into the wort.
6. I pitch my starter, usually ~0.5L pitching the full volume or 1L that has settled and been decanted.
******
7. After fermenting for 3-4 weeks (and given the occasional swirl to rouse yeasties), I bring the bucket into the kitchen for bottling. I take a small sample with ym wine theif for gravity measurement.
8. Boil a couple of cups of water and mix up my sugar. Pour that into the bottle bucket.
9. On these three batches I rigged up a little tube that let me cleanly suck the beer up the racking cane and into the tubing until I was confident I could pinch it off and then let it flow into the bucket and maintain the vacuum. When I do this, a little air is inevitably mixed in initially as the wort starts to fill the bucket. Once the wort is going, it submerges the end of the tube and the wort is now flowing (theoretically) without air getting in.
Note: Sometimes the tube doesn't fill all the way up and the beer flows in the tube for a few seconds with some airspace. If I briefly pinch off the tubing, this airspace goes away.
10. Towards the end of the racking to the bottling bucket, I tilt the bucket a little to get the last of the beer. Some of the loose yeast cake is also pulled in, which I figure doesn't matter much and just aids in carbing the beer quicker. As the dregs are racked out, the cane starts to gurgle and I pull it out to avoid getting too much air mixed in, though I know some does.
11. Once transferred to the bottling bucket, I consider it mixed enough as it flows in from the bottom up. I do no stirring or anything at this point to the beer directly.
12. I have a very short piece of tubing on my bucket's spigot that is just long enough to stick my bottling wand in and hold it in place. I open the spigot all the way and let the wand fill. I use the spring loaded wand.
13. Now I start bottling, just put the bottle under the wand, push up a little and fill until it is just at the top with the wand still in the bottle. When I remove the wand this leaves a nice and small amount of headspace. When the filling starts it does sound like it sprays a little and I'm sure a little more air mixes in, but what can you do about that?
14. Now I cap the bottles (I don't use the better O2 sealing caps as the beer doesn't sit around that long). They get put into the bottle boxes and stored in my closet until carbed up.

So please tell me, how am I getting enough O2 in my beers to get noticeable oxidation (not that I've ever noticed it, but it seems that it isn't smack you over the head noticeable, just present as a flavour. I also don't know what it really tastes like, so maybe I am just missing it).
 
I am interested in hearing what the more seasoned veterans will have to say, but I did notice you are transferring to a bucket once the wort is cooled to between 80-85. All of my notes indicate 80 as the highest acceptable temperature (80+ is oxidation, 80- is aeration).

See http://www.howtobrew.com/section1/chapter6-9-3.html
 
I didn't see any problems jump out at me as you related your process.

Aeration prior to adding yeast is good.

The part about stirring your yeast to rouse it...I usually grab my bucket at the base (while on a counter) and swirl/drag it in a circle without the base leaving the surface. This way I'm not stirring it by dipping a spoon into it.

As for your priming process...I never add water to my beer once the wort is topped off and yeast added. I rack off 1-2 cups of beer and boil my priming sugar in it then add it to the bottling bucket.

That's all I have to offer.
 
I'm convinced that your "oxidation problem" problem isn't really a problem. The judges probably just didn't like your beer so their go-to answer is ding you for oxidation. I get dinged for oxidation all the time, and I've never once tasted it in any of my brews. I did notice some off flavors coming from a batch that I used the "bad" nottingham on though. "They" called it oxidation.
I'm curious what any seasoned judges would have to say about all of this. :mug:
 
I get dinged for oxidation all the time, and I've never once tasted it in any of my brews.

If you're looking for papery, cardboardy flavors oft ascribed to oxidation, you might be missing it. When I taste oxidation (and I've tasted it both in commercial and HB beers), the beer often just seems rather flat and lifeless rather than those classic descriptors. Oxidation can actually be complementary in some beers, particularly big beers like barleywines etc, as a sherry-like or vinous character.

Oxidation does exist, I assure you. ;)

Gremlyn1 - there's nothing about your process that suggests oxidation in any way, so I'm afraid I can't offer much help here.
 
I think your process looks solid, and especially with bottle conditioning you get a short extra round of fermentation that should clean up the beer in the bottle.

That said, the problem could be bottle conditioning, some time yeast in suspension can cause off flavors. With comps you don't have much control over how the bottle is handled, so the yeast at the bottom might get disturbed and might not have had a chance to settle back to the bottom before the judge tastes it.

I'm not sure if this is a problem though, Sierra Nevada bottle conditions their beers, and I don't notice them being yeasty.
 
How aggressively do you "rouse" your yeast, and at what stage in fermentation?
 
How aggressively do you "rouse" your yeast, and at what stage in fermentation?

I pick the bucket up and give it a gentle swirling circular motion for 30-60 seconds about a week into the fermentation. Maybe again two weeks in.

I'm glad everyone else thinks I'm doing this right... I was starting to wonder if I was crazy :p
 
The only things I see that could cause it (but still seem unlikely) have already been mentioned. I.E. the cooling before racking to the fermenter...and the rousing the yeast...especially sort of 'late' in the fermentation. At that late stage there isn't much CO2 being produced and it would be easier to let air in...but that still seems unlikely. It shouldn't be necessary to rouse it to hit your FG anyway.

I had some slight oxidation in two of my HBT brews too. Sherry-ish in one and vegetal in another. I never really noticed the vegetal note just knew something was off. Now I went back and tasted that brew and I can taste it.
 
The only things I see that could cause it (but still seem unlikely) have already been mentioned. I.E. the cooling before racking to the fermenter...and the rousing the yeast...especially sort of 'late' in the fermentation. At that late stage there isn't much CO2 being produced and it would be easier to let air in...but that still seems unlikely. It shouldn't be necessary to rouse it to hit your FG anyway.

I had some slight oxidation in two of my HBT brews too. Sherry-ish in one and vegetal in another. I never really noticed the vegetal note just knew something was off. Now I went back and tasted that brew and I can taste it.

I had one of my ESBs last night night and couldn't pick up the oxidation, but I could taste all the rest of the notes pretty well. I also remembered I had made the dregs of my ESB into a 12-oz bottle that I purposely shook the crap out of to oxidise it. When comparing the two, I could taste that the shaken one was definitely not right, but I couldn't peg 'cardboard' as the flavour, it was just off from the 'good' ESB.

As for the swirling, I wouldn't imagine that O2 is getting in, and I wouldn't think oxidation would be possible without O2 ;) As far as I can tell my fermentors seal well. I've never had a lack of airlock activity that would indicate one is leaking significantly. Really the only reason I swirl is to off-gas the CO2 trapped in the yeast cake, which I assume/think/hope/expect gives me a tighter packed cake. Could be complete bollucks, but it makes sense (to me).
 
As a home brewer, it appears your process is not much different in terms of O2 exposure than most of us. Most beer oxidation flavor occurs in the bottle after conditioning. Yeast fermenting in the beer during conditioning use up the oxygen intorduced at bottling. Bottle conditioned beers have a much better shelf life (read low oxidation flavors) than other packaged beers. The question I have, is once your beer is in the bottle, how long and at what temperature does it sit to bottle condition? Also, after it is bottle conditioned, how is it stored before taken or shipped to the competition? What are the "shipping" conditions and how is the beer stored before tasting? From personal experience I have seen commercially packaged, non-bottle conditioned beers develop very strong oxidation flavors in 7 days if not stored cold. These beers were packaged on a commercial bottling line where steps are taken to reduce or eliminate O2 as much as possible (on average 0.1 ml of air or less per bottle). So your oxidation flavor is likely what happened to the bottle after packaging and conditioning if it is truely oxidation.

Dr Malt :)
 
I am interested in hearing what the more seasoned veterans will have to say, but I did notice you are transferring to a bucket once the wort is cooled to between 80-85. All of my notes indicate 80 as the highest acceptable temperature (80+ is oxidation, 80- is aeration).

See http://www.howtobrew.com/section1/chapter6-9-3.html

I thought that as long as you are under 100, you won't have issues with sloshing the beer around.
 
I store the beer for 3 weeks in my closet, which ranges from 70-80F depending on the time of year. After that, I start sticking them in the fridge and drinking them.

The bottles sent to the competition had sat 4 weeks in the fermentor, and 2 weeks in the bottle before I shipped them out. They then went through normal ground shipping conditions (which I'm sure are superb conditions for beer) and apparently were stored in a room that stayed in the mid to upper 60's for about a week before being shilled and served at the comp.

I'm definitely feeling much better about my process now... thanks everyone :)
 
Thats not at all true. Redox reactions (where one thing is oxidized and another reduced), do not require oxygen at all. Oxygen happens to be a very strong oxidizing agent.

http://en.wikipedia.org/wiki/Oxidizing_agent

Touche... been a while since I took a general chem class. Iodine and chlorine are both oxidisers, but I doubt either are present in enough quantity to do harm. I do use iodophor...
 
3. To transfer my wort to the boil kettle, I just open up the valve on my MLT (5 gal Rubbermaid with brass ball valve) and let it flow, after vorlaufing of course. It probably flows in from a height of 18" at most, obviously the height reduces as the kettle fills. The does cause a lot of splashing.

I thought I read ANY time the wort is hot you risk problems if you splash it around? Could you use a hose at this point from the valve into the bottom of the kettle? Seems like it couldn't hurt at least.
 
I thought I read ANY time the wort is hot you risk problems if you splash it around? Could you use a hose at this point from the valve into the bottom of the kettle? Seems like it couldn't hurt at least.

I don't think you need to be worried about spashing of wort BEFORE the boil. I mean, your sparge waters spashes around as you trickle it over the grains anyway, so it really doesn't matter if you CAREFULLY drain to the kettle.

Plus, my wort splashes around like hell when I boil it. Doesn't yours?

As far as I know, the boiling process drives off any oxygen that's in the wort, so you don't have to worry about that. You only need to worry about splashing it around while it's hot and you are DONE boiling.
 
I stand corrected. Here's some info I just found on BYO.com (http://***********/stories/techniques/article/indices/7-aeration/1671-winning-the-air-wars)

BYO said:

The Hot Zone
Hot-side aeration describes the pick-up of air during the “hot” stages of the brewing process. However, it is really only a concern during the mash and sparging stages. During the mash and sparge, there are certain enzymes present in the malt that, when in the presence of oxygen, can combine with malt compounds and form the flavor and aroma compounds that we perceive as oxidation. Therefore, taking care not to splash the wort too much during mashing, sparging, and runoff into the kettle will help you avoid these flavor and aroma compounds. As soon as you begin the boil, the enzymes will be destroyed, and the risk of oxidation at this point is then eliminated. So don’t worry about stirring and splashing during the boil. Boiling will drive any remaining oxygen out of the wort, and many large commercial breweries actually aerate the wort during or immediately after boiling to help precipitate tannins and to strip unwanted volatile gasses from the wort. But remember, because boiling strips the wort of oxygen, it is even more important to aerate the wort when you pitch the yeast.

How about that. I've been brewing for 12 years, AG for the last few. I've been thinking about it all wrong.

but, you know what? My beer is still good, and I don't care. :mug:
 
:ban:

I had a friend come over this weekend to teach me how to brew. We did an all grain that is turning out to be a sweet stout. At least according to the software. I've been reading like a maniac ever since and was pretty sure I had read that. Plus, it seemed kind of obvious to me that this would be an obvious thing to try given the problem.
 
Hermit and Walker-san, Listen to this pod cast interview:

Homebrewing beer. In the episode of Brew Strong, Jamil and John welcome head of the Brewing Science program at UC Davis, Dr. Charles Bamforth to the show to help explain and cover hot side aeration. Dr Bamforth explains some of the myths and legends surrounding the controversial topic and instructs brewers on how to deal with HSA based on his own extensive research. This show should not be missed by homebrewers and professionals alike!

It is vary informative, and up to date with many peoples views on the topic.
 
just a thought - is it possible that shipping beer under bad conditions (e.g. hot temperatures) could speed up things like autolysis and oxidation?

I had an IPA that got dinged in a comp this summer for severe autolysis aroma (rotten egg). In the rest of the batch, I never detected the slightest rotten egg aroma. I was wondering if the really hot (100+*F) shipping/holding/shipping temps may have caused it?
 

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