Why is one bad, and one recommended? Aren’t they - ultimately - the same thing???
There’s a lot if debate on whether hot side aeration (HSA) is real or myth. HSA reportedly reduces the shelf life of the beer fatty acids in the beer being oxidized.
Aeration after the wort is cooled is needed because the yeast uses the O2 to metabolize and multiply. This you want, HSA you want to avoid.
According to Dr. Charles Bamforth, the bottom line is that HSA is technically real, however not a meaningful concern, because the yeast will clean up issues during fermentation. Don’t worry about splashing your hot wort a little. Make sure you’re creating optimal conditions for fermentation (make an appropriate starter, provide oxygen in the wort, control temp, etc.).
I measure my wort in one bucket and dump it into the brew kettle.
Never had any issues.
We are kind of kicking this around in another thread but once again I think on a homebrewing level it is difficult to HSA your wort. It would be an interesting experiment to do two batches or split a batch then purposely aerate one by violently splashing or even introducing pure O2. Then see what the results are. I have seen comments that someones beer was oxidized but was that the problem or did something else occur that aeration was blamed.
Just using a minimal amount of care should be enough to prevent HSA. Don’t you think?
HSA is the kind of thing I’m not looking to prove, for or against. I show a low level of care by not splashing hot wort around, whether it matters or not, and it takes little effort. I have better things to worry about.
To answer your question, oxygenating wort after you are done fermenting is where I would worry most. Packaging is the most boring part of this thing we do, but it isn’t hard. Always be a good janitor and packager. It prevents a lot of problems before they start.
John Palmer states that oxidation is probably the most common problem in beer, including commercial beers. If the wort is exposed to oxygen at temperatures above 80f the beer will eventually develop wet cardboard or sherrylike flavors.
I know the yeast will clean up many off flavors created during fermentation but I did not know the yeast can clean up compounds that were oxidized.
[quote=“HD4Mark”]We are kind of kicking this around in another thread but once again I think on a homebrewing level it is difficult to HSA your wort. It would be an interesting experiment to do two batches or split a batch then purposely aerate one by violently splashing or even introducing pure O2. Then see what the results are. I have seen comments that someones beer was oxidized but was that the problem or did something else occur that aeration was blamed.
Just using a minimal amount of care should be enough to prevent HSA. Don’t you think?[/quote]
http://brulosophy.com/2014/11/18/is-hot ... t-results/He did the experiment, taste testers were not able to conclusively detect a difference between the HSA and non-HSA beers, but it sure seemed he worked to maximize HSA, so if it were as bad as all that I would think the distinction WOULD have been conclusive.
There were several places in the procedure where one might call into question the scientific method, but it sure seems like a good approach. It’s just impractical to do the number of trials really necessary with homebrew-sized batches.
[quote=“JMcK”]We are kind of kicking this around in another thread but once again I think on
http://brulosophy.com/2014/11/18/is-hot ... t-results/He did the experiment, taste testers were not able to conclusively detect a difference between the HSA and non-HSA beers, but it sure seemed he worked to maximize HSA, so if it were as bad as all that I would think the distinction WOULD have been conclusive.
There were several places in the procedure where one might call into question the scientific method, but it sure seems like a good approach. It’s just impractical to do the number of trials really necessary with homebrew-sized batches.[/quote]
The problem with the experiment is that he tested the beers fresh and stopped there. From what I understand, HSA is supposed to cause a shelf stability problem. The samples should have been tested over time using the same procedure each time. Based on that, I consider the experiment inconclusive.
[quote=“DUNNGOOD”]John Palmer states that oxidation is probably the most common problem in beer, including commercial beers. If the wort is exposed to oxygen at temperatures above 80f the beer will eventually develop wet cardboard or sherrylike flavors.
I know the yeast will clean up many off flavors created during fermentation but I did not know the yeast can clean up compounds that were oxidized.[/quote]
No doubt oxidation is a big problem, but some of that has to be due to packaging issues. Have you personally encountered hot side aeration in your process? I appreciate the notion that it’s a good idea to be careful, but I have crashed my process before, splashing all kinds of hot wort (not proud moments), and it didn’t make a difference. How hard would one have to try to cross the line? Again, simple steps make the whole argument easy to avoid, but I don’t think you can live in fear of this.
I believe I have detected sherry or cardboard flavors in beer samples. And it has been pointed out at some BJCP companions.
The way I understand it is once the compounds are oxidized in the hot wort the off flavor will not show up till latter. So beers that are packaged and used soon my not develop this flavor. I do hear this off flavor being described in beers imported that have been packaged for a period of time.
I’m in the process of testing this now. My hypothesis is that it is extremely unlikely that unfiltered, unpasteurized, bottle conditioned beer will develop oxidation off-flavors, because the living yeast in the bottle will scavenge any and all oxygen as it carbonates the beer. To test this, when I bottled my last three batches, the very last bottle was deliberately and highly oxygenated. I marked them and set them all aside with one normally-filled bottle from each batch. I will taste each oxygenated bottle side-by-side with a normally-filled bottle approximately six months from the bottling date. I’ll either have good examples of horribly oxidized beer, or I’ll have to experiment further with a larger sample size. My first results will be documented in mid October…
Ken, I agree that oxygen introduced on the cold side may be used up by the yeast. As I bottle and store some beers I would interested in the results of you test.
The off flavor that I am suggesting is hot side oxidation was the hot wort is exposed to oxygen. Yeast is good at cleaning up off flavors it has made from fermentation but once these fatty acids and other compounds are oxidized I don’t believe that the yeast can clean up this flavor. I am interested in find out more on this subject.
I tend to oxygenate most all of my beers at around 100*F. Due to groundwater temps and laziness, I usually cool to around 100 then drain from the kettle into the fermenter then throw it into the fridge to cool the rest of the way. I don’t use a hose, so the beer flies out the ball valve of the kettle and splashes into the fermenter a few feet below. I imagine it picks up a good deal of oxygen this way. I’ve kept dozens of beers made this way for several months up to 3 years or more without any unusual oxidation. When I have noticed the occasional oxidized beer, its almost always been traceable back to poor bottling practices. HSA doesn’t really seem like a concern IME.
