Hot Wort Aeration

doug293cz said:

Sorry, but I don't agree that's a reasonable assumption, even though it is a possibility and can't be ruled out. Need to have some way to make HSA a more believable suspect. Need to have an experiment with & without HSA followed by aging. And, it would be nice to have multiple experiments. We'll just have to disagree until some more empirical evidence is available.

Brew on

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So until you "see" it with your own eyes you are going to discount it completely? Do you not think black holes exist?

mattd2 said:

So until you "see" it with your own eyes you are going to discount it completely? Do you not think black holes exist?

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Yeah, I believe in black holes. There are lots of readily available explanations of the evidence.

I don't doubt that hot wort can oxidize. What I doubt is that HSA is a significant effect that homebrewers need to worry about. Where are the reports that show HSA has caused noticeable degradation of homebrew, and not just speculation that it might have been a cause?

Brew on

doug293cz said:

Yeah, I believe in black holes. There are lots of readily available explanations of the evidence.

I don't doubt that hot wort can oxidize. What I doubt is that HSA is a significant effect that homebrewers need to worry about. Where are the reports that show HSA has caused noticeable degradation of homebrew, and not just speculation that it might have been a cause?

Brew on

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Where are the reports that it has not, and not just speculation that it might not have been a cause?
As I understand it the hot wort does not oxidise causing off flavours - oxygen binds with compounds in the wort at high temperatures to form relatively stable compounds. These later slowly release the oxygen back into the finished beer which leads to oxidation.

So if it can be proven that the oxygen does bind with compounds in the wort at higher temps and that the oxygen is later released, would you then accept that HSA does exist?

I think an experimental batch should be done. How about aerating the mash strike and the wort before cooling with pure 02 injection vs a controlled batch? Did Brulosopher ever get his experiment off the ground?

forgive me for choosing to listen to Charlie Bamforth from five years ago instead of a decade's worth of kneejerk forum posters.
http://www.thebrewingnetwork.com/shows/475

He gets paid to say that stuff remember. Forum members only wanna make good beer.


By the way. Just listened to the podcast you referenced labelled 'Hot Side Aeration' and during the hour long podcast they only discussed hot-side aeration for 2 minutes starting at the 28 minute mark and Bamforrth only makes comments like "no idea' and "who knows".

mattd2 said:

So until you "see" it with your own eyes you are going to discount it completely? Do you not think black holes exist?

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Just to derail this thread even further...some black holes are actually very bright

Do you mean they emit light themselves? Or that the objects attracted to them are reflecting light?

Dr. Bamforth does mention that when he was working for Bass the Carling Black Label made in Liverpool had a harsh grainy taste until they reduced oxygen in the brewhouse.

orangehero said:

Dr. Bamforth does mention that when he was working for Bass the Carling Black Label made in Liverpool had a harsh grainy taste until they reduced oxygen in the brewhouse.

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Examples from industrial scale brewing may or may not be applicable to homebrew scale. Still looking for credible reports of detrimental effects of HSA on homebrew.

Brew on

Let us know what you find.

Come on people. You can't have listened to that podcast and come away with the notion that hot side aeration is a problem that needs to be addressed. He even directly addresses the cardboard flavor, which isn't necessarily due to oxidation. The whole point is, no matter how well you care for your beer, it degrades over time. As far as HSA, he states theres no direct evidence of it. While there is very clear and severe evidence of oxidation issues on the cold side. If you have cardboard or soy sauce, its a 99.9% chance that its something you did or didn't do on the cold side...period.

Do not try to argue based on a lonely sentence or two that was said. What I wrote above is essentially the summary and overall point. If you can't plainly see the results that they came to, at least admit your bias.

mattd2 said:

Correlation does not imply causation. Anecdotal evidence does not mean HSA is a lie. I don't think you will get any evidence of proven HSA in homebrewing. Not because it is not there, but because it is so hard to pin point as a cause. One would have to brew a beer and significantly aerate it while it is hot. And then ferment in ideal conditions, without introducing any additional oxygen after alcohol has started to be produced. Then age for enough time for the oxygen to be released... It is not going to happen at a homebrewing level.

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I already stipulated that anecdotal evidence does not prove anything. So, why bring it up again?

I did find an experiment that was conducted in 2006 and reported on the Basic Brewing web site. They did a very well controlled experiment (way better than most homebrew experiments) to attempt to determine if HSA had detrimental effects on homebrew. They did three tastings starting at about two weeks after bottling, and the final tasting after 6-7 months. The experiment and tasting results are described in the following three podcasts:

1. First
2. Second
3. Third

My takeaway from the experiment is that while there were differences in flavor that might have been related to the HSA, those differences diminished with time. Any effect was greater on new/green beer than beer with more time to bottle condition. The reduction of differences is consistent with Dr. Bamforth's assertion (in both of the 2009 and 2014 interviews linked elsewhere in this thread) that the yeast will clean up a lot of whatever HSA might have done to the wort. And though there were taste differences, the tasters didn't believe the differences where a significant detriment. And, in order to have these taste differences, they had to resort to aeration methods far beyond what would normally occur in typical homebrew processes. I believe the experiment supports the assertion that HSA does not have significant detrimental effects in a typical homebrew environment. I am not saying that wort does not oxidize on the hot side, only that it doesn't cause significant problems for homebrewers.

I also dug around more on Google, and did run across a few anecdotal reports of problems attributed to HSA. Like most anecdotal cases, there was no well controlled experimentation to verify. So, these cases don't prove anything either, but the anecdotal reports are not all one sided (which was my earlier perception.)

Brew on

grathan said:

I think an experimental batch should be done. How about aerating the mash strike and the wort before cooling with pure 02 injection vs a controlled batch? Did Brulosopher ever get his experiment off the ground?

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I PM'ed the Brulosopher a couple days ago, and his HSA experiment is still in the queue. No ETA was given. Be interesting to compare his experiment with the one reported on Basic Brewer (which I linked to earlier.)

Brew on

Just as Budweiser kreusens the beer that they air scrub, the experiments used bottle conditioned beer. Perhaps the bonded 02 molecules come apart at the time co2 is present. In these cases there would still be live yeast to deal with it.

Any money spent on an hsa experiment would be better saved towards a keg system.

I accidentally did an HSA experiment last year. I decided that instead of running the air pump in the fermenter I'd do it in the keggle (less chance of foam overflowing). Unfortunately, in my eagerness to try something different I started pumping air in as soon as I turned off the propane. So I aerated from boil down to pitch @70F (15-20min).
I've never had a cardboard beer and if HSA is the prime factor then I'd say that oxygenation after the boil doesn't cause HSA. Perhaps before the boil is different (although I use tap water plus salts and normally don't let it degas overnight).

The Brulosopher's ExBEERiment on HSA is complete and results posted here. More evidence that HSA has little to no effect for typical homebrewers. I am officially done worrying about it.

Brew on

It's weird that he quotes Palmer saying the bound oxygen compounds break down over time, and yet then proceeds to disprove him by drinking the entire keg by the day after he posts that.

johngaltsmotor said:

I accidentally did an HSA experiment last year. I decided that instead of running the air pump in the fermenter I'd do it in the keggle (less chance of foam overflowing). Unfortunately, in my eagerness to try something different I started pumping air in as soon as I turned off the propane. So I aerated from boil down to pitch @70F (15-20min).
I've never had a cardboard beer and if HSA is the prime factor then I'd say that oxygenation after the boil doesn't cause HSA. Perhaps before the boil is different (although I use tap water plus salts and normally don't let it degas overnight).

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You did exactly what AB does. They force air through the hot wort to help drive off DMS. Also, Belgian brewers that use coolships spray the hot wort into the coolships to expose them to the bugs floating around in the air for wild fermentations. If they don't worry about "HSA" I sure as heck won't either. Bamforth backed this up in a brewing course I took also, saying that HSA really does not exist.

grathan said:

It's weird that he quotes Palmer saying the bound oxygen compounds break down over time, and yet then proceeds to disprove him by drinking the entire keg by the day after he posts that.

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Yeah, I would have liked to see aging of the test brews in this experiment. However, in an earlier experiment by different experimenter(s) (links here), no difference was found due to aging.

Brew on

Can we sticky this? This is one of those arguments that comes up once in a while with someone having their heels dug in pretty deep.

If anyone knows how to contact BYO Mr. Wizard (Ashton Lewis, who has a master’s degree in brewing science from UC Davis) it would be interesting to get references for his conclusions.