[denny]

narcout said “it's pretty unlikely you're going to notice any ill effects from small scale, additional oxygenation on the hot side.” Emphasis on hot side.

I think that’s right. There are definitely “noticeable effects from oxygen during other processes.” But, most of those effects are from cold side oxidation if you aren’t doing low oxygen brewing (narcout’s assumption).

I've seen at least one instance that proves my point.  It is possible on the hot side whether you brew low oxygen or not.

Can you please elaborate?

I did say it was good practice to avoid HSA regardless of whether one is brewing LODO.

Yes, you did, and there's no doubt of that.  I have seenm someone have trouble with large amounts of air in their runoff lineof and the beer was badly oxidized despite the rest of the processes being good.  Not conclusive, of course, but an interesting data point.

[Robert]

Interesting,  I thought a more rigorous boil was desired.  I'll have to turn my burner down and give it a try.

The idea of a long, vigorous boil was to drive off DMS.  In fact, it takes at least 30 minutes on heat to convert the DMS precursor,  SMM, into DMS,  after which just a few minutes of an open boil with lots of rolling and bubbling will drive it off.  BUT.  It is very rare today to find a malt that contains the precursor, although it was common in the palest Pilsner malts decades ago, whence the old advice.  For all other purposes you can keep the lid mostly on, allowing you to reduce the heat, and just maintain a simmer providing the good rolling circulation which you need to coagulate protein and well utilize your hops. Then lid off and blast it for a bit, there are still other volatiles fo blow off. One trick I like for this is to heat the kettle asymmetrically. This will create a lot of movement and turbulence. (Here's an indicator:  if your boil off is under 10%, even as low as 6%, you're probably doing well on the thermal stress.  Above that, and especially when you hit 12%, wort will taste stale and get staler faster.) 

(I had a long brewing hiatus too, in the late 90s to early 00s, and it seemed not much had changed.  In the last 10 years, it seems everything we knew has been upended!)

[mabrungard]

It is very rare today to find a malt that contains the precursor, although it was common in the palest Pilsner malts decades ago, whence the old advice. 

Rob, I haven't found any evidence that pils malts don't have SMM in them. Maltsters have tried to find a way to malt their barley and kiln them to a low color without still having SMM. All kinds of drying and heating schemes have been tried, but the malt with successful SMM reduction had darker color.

I'm unaware that maltsters have succeeded in that quest. SMM and DMS are still a potential problem, but I do agree that the old ways of doing things weren't necessarily the best.

[Robert]

Martin, I admit it's true that the Pils malts do still have some SMM.  But what I've experienced, and what the maltsters indicate, is that they have greatly reduced it in most of their Pilsner malts.  Maybe not the very palest, less modified ones, but these are now specialty products.  Most of the Pilsner malts we encounter, and all of the other base malts, have it below the level that would justify its being a focus of attention anymore.  It would be very difficult, I think, for most homebrewers to so far reduce the intensity of their boil process that they would fail to deal with the level of SMM they will find in most any malt, including pale Pilsner.   The much greater problem is the danger of wort damage through over-boiling out of a misplaced fear of phantom DMS, it would seem -- especially when trying to make a delicate, fresh-tasting Pilsner, which is ironically when homebrewers are most often advised to boil long and hard.  As you say, DMS is a potential problem, but thermal stress is a dead certainty.   

Sure wish the audio of your seminar on boiling was available, I'd really looked forward to it.

[JT]

My current idea of "open boil." 

I brew mostly German lager styles using Weyermann malts. 

[The Beerery]

I am at 3% boil off for a 60 minute boil.  I boil out of a 3”tc with a boil coil at 45%.  Zero dms issues. PH is also a major factor in DMS. Get those pH’s in the 5.4 range for the bulk of the boil.

Sent from my iPhone using Tapatalk

[hopfenundmalz]

narcout said “it's pretty unlikely you're going to notice any ill effects from small scale, additional oxygenation on the hot side.” Emphasis on hot side.

I think that’s right. There are definitely “noticeable effects from oxygen during other processes.” But, most of those effects are from cold side oxidation if you aren’t doing low oxygen brewing (narcout’s assumption).

I've seen at least one instance that proves my point.  It is possible on the hot side whether you brew low oxygen or not.

Can you please elaborate?

I did say it was good practice to avoid HSA regardless of whether one is brewing LODO.

Yes, you did, and there's no doubt of that.  I have seenm someone have trouble with large amounts of air in their runoff lineof and the beer was badly oxidized despite the rest of the processes being good.  Not conclusive, of course, but an interesting data point.

Years back Vinnie C had said to remove all of the air from your hoses. That was good advice.

[ynotbrusum]

If you do a recirc HERMS, you simply start the recirc before immersing the return line/halo.  Then with a tight system, you should be good to go.  After a couple years of low Ox brewing, I tried a Helles without the low Ox methods and found it to be heavily oxidized, almost as badly as the German beers I buy at the local bottle shop.

I am spoiled, I know, but it truly is readily noticeable and I am not being a beer snob - if I could get fresh enough German beers, I would happily buy them.  I go back frequently to buy German beers that are as fresh as I can get and while I am always hopeful, oxidation typically is very noticeable.  I run them by non-BJCP friends to blindly ask them what they think and “lack of freshness” is the most frequent comment when the commercial beers are sampled as compared to my Low Ox versions.  YMMV and I wish it weren’t so in my experiences.

[denny]

narcout said “it's pretty unlikely you're going to notice any ill effects from small scale, additional oxygenation on the hot side.” Emphasis on hot side.

I think that’s right. There are definitely “noticeable effects from oxygen during other processes.” But, most of those effects are from cold side oxidation if you aren’t doing low oxygen brewing (narcout’s assumption).

I've seen at least one instance that proves my point.  It is possible on the hot side whether you brew low oxygen or not.

Can you please elaborate?

I did say it was good practice to avoid HSA regardless of whether one is brewing LODO.

Yes, you did, and there's no doubt of that.  I have seenm someone have trouble with large amounts of air in their runoff lineof and the beer was badly oxidized despite the rest of the processes being good.  Not conclusive, of course, but an interesting data point.

Years back Vinnie C had said to remove all of the air from your hoses. That was good advice.

This was a case of someone using a way oversized hose and not getting a tight connection.

[Big Monk]

It seems there is a great deal of discussion pertaining to Hot Side vs. Cold Side of the brewing process.  Instead, shouldn’t the discussion be Pre-Aeration and Post-Fermentation?  Perhaps I simply don’t understand the conversation.  But we want oxygen in the wort when we pitch.  Then, we work to avoid inclusion of oxygen after fermentation.

I want as much splashing as possible when I pump my wort from the BC through my plate cooler and into the fermenter; this can only help fermentation.

So why would oxygen on the hot side be of any concern?  Am I missing something?

You want a controlled addition of oxygen at the right time, i.e. in cooled, pre-fermentation wort. Oxygen is orders of magnitude less reactive with the wort  at pitching temperatures than at mash temps. The rates at which oxygen will affect a chilled wort are such that an active pitch of yeast will chew through it before it could ever cause any damage.

[goose]

Although I agree that appropriate steps should be taken to minimize oxygen uptake during the mash, runoff, and boil steps of the brewing process, I remember a paper that was presented at the 2014 Homebrew Con in Grand Rapids about HSA.  It said in a nut shell that it was not as big a problem as originally thought.  They tested an ESB that was brewed using good brewing practices (the control beer) and also where they oxygenated the hell out of the wort during mash and boil stages.  They evaluated the beers when fresh, after 10 weeks in the bottle, and after 20 weeks in the bottle to determine if the excessive O2 had any adverse effects when compared to the control beer.  Mind you, I would never try to repeat this experiment but the results were interesting.  We also got to sample some of the control beer and the 'excessively oxygenated" beers so that we could see for ourselves.

The link to the paper is:  https://www.homebrewersassociation.org/attachments/presentations/pdf/2014/Effects%20of%20Hot%20Side%20Aeration%20of%20Wort,%20Mash%20and%20Sparge%20Water.pdf

There is also a live recording of the seminar on the AHA web site.

I am sure that noticeable effects could appear after longer aging but this was an interesting experiment.  Of course, YMMV.  Denny, maybe you could weigh in on this a bit more since you have had a lot more experience with oxidized beers.

[Big Monk]

Although I agree that appropriate steps should be taken to minimize oxygen uptake during the mash, runoff, and boil steps of the brewing process, I remember a paper that was presented at the 2014 Homebrew Con in Grand Rapids about HSA.  It said in a nut shell that it was not as big a problem as originally thought.  They tested an ESB that was brewed using good brewing practices (the control beer) and also where they oxygenated the hell out of the wort during mash and boil stages.  They evaluated the beers when fresh, after 10 weeks in the bottle, and after 20 weeks in the bottle to determine if the excessive O2 had any adverse effects when compared to the control beer.  Mind you, I would never try to repeat this experiment but the results were interesting.  We also got to sample some of the control beer and the 'excessively oxygenated" beers so that we could see for ourselves.

The link to the paper is:  https://www.homebrewersassociation.org/attachments/presentations/pdf/2014/Effects%20of%20Hot%20Side%20Aeration%20of%20Wort,%20Mash%20and%20Sparge%20Water.pdf

There is also a live recording of the seminar on the AHA web site.

I am sure that noticeable effects could appear after longer aging but this was an interesting experiment.  Of course, YMMV.  Denny, maybe you could weigh in on this a bit more since you have had a lot more experience with oxidized beers.

The problem with experiments that attempt to analyze the affect of HSA is that their control beer is really not a control beer. If you mash in with oxygen saturated water, and are careful on the cold side, the resulting beers won't differ significantly, i.e. the beer is already oxygenated heavily at mash in.

Remove the Low Oxygen/Standard argument for a second and just contemplate what a real control beer for an HSA experiment would be and realize that it would two separate but identical batches, with one devoid of oxygen throughout the process and one created just as in the presentation posted above. Then compare the results.

[goose]

Although I agree that appropriate steps should be taken to minimize oxygen uptake during the mash, runoff, and boil steps of the brewing process, I remember a paper that was presented at the 2014 Homebrew Con in Grand Rapids about HSA.  It said in a nut shell that it was not as big a problem as originally thought.  They tested an ESB that was brewed using good brewing practices (the control beer) and also where they oxygenated the hell out of the wort during mash and boil stages.  They evaluated the beers when fresh, after 10 weeks in the bottle, and after 20 weeks in the bottle to determine if the excessive O2 had any adverse effects when compared to the control beer.  Mind you, I would never try to repeat this experiment but the results were interesting.  We also got to sample some of the control beer and the 'excessively oxygenated" beers so that we could see for ourselves.

The link to the paper is:  https://www.homebrewersassociation.org/attachments/presentations/pdf/2014/Effects%20of%20Hot%20Side%20Aeration%20of%20Wort,%20Mash%20and%20Sparge%20Water.pdf

There is also a live recording of the seminar on the AHA web site.

I am sure that noticeable effects could appear after longer aging but this was an interesting experiment.  Of course, YMMV.  Denny, maybe you could weigh in on this a bit more since you have had a lot more experience with oxidized beers.

The problem with experiments that attempt to analyze the affect of HSA is that their control beer is really not a control beer. If you mash in with oxygen saturated water, and are careful on the cold side, the resulting beers won't differ significantly, i.e. the beer is already oxygenated heavily at mash in.

Remove the Low Oxygen/Standard argument for a second and just contemplate what a real control beer for an HSA experiment would be and realize that it would two separate but identical batches, with one devoid of oxygen throughout the process and one created just as in the presentation posted above. Then compare the results.

That would be a good follow-up experiment.  Obviously, there have been changes in procedures since 2014 and there is more information out there but for general homebrewing (if you are not a fierce competition brewer), I think that we might be over-analyzing things.  I don't dispute your post, I am just thinking, RDWHAHB.  If your beer tastes good to you and your friends, all is good with the world.  If you start having oxidation problems, then it's time to take a look at your process.

[denny]

Good on ya, Goose.

[Big Monk]

Although I agree that appropriate steps should be taken to minimize oxygen uptake during the mash, runoff, and boil steps of the brewing process, I remember a paper that was presented at the 2014 Homebrew Con in Grand Rapids about HSA.  It said in a nut shell that it was not as big a problem as originally thought.  They tested an ESB that was brewed using good brewing practices (the control beer) and also where they oxygenated the hell out of the wort during mash and boil stages.  They evaluated the beers when fresh, after 10 weeks in the bottle, and after 20 weeks in the bottle to determine if the excessive O2 had any adverse effects when compared to the control beer.  Mind you, I would never try to repeat this experiment but the results were interesting.  We also got to sample some of the control beer and the 'excessively oxygenated" beers so that we could see for ourselves.

The link to the paper is:  https://www.homebrewersassociation.org/attachments/presentations/pdf/2014/Effects%20of%20Hot%20Side%20Aeration%20of%20Wort,%20Mash%20and%20Sparge%20Water.pdf

There is also a live recording of the seminar on the AHA web site.

I am sure that noticeable effects could appear after longer aging but this was an interesting experiment.  Of course, YMMV.  Denny, maybe you could weigh in on this a bit more since you have had a lot more experience with oxidized beers.

The problem with experiments that attempt to analyze the affect of HSA is that their control beer is really not a control beer. If you mash in with oxygen saturated water, and are careful on the cold side, the resulting beers won't differ significantly, i.e. the beer is already oxygenated heavily at mash in.

Remove the Low Oxygen/Standard argument for a second and just contemplate what a real control beer for an HSA experiment would be and realize that it would two separate but identical batches, with one devoid of oxygen throughout the process and one created just as in the presentation posted above. Then compare the results.

That would be a good follow-up experiment.  Obviously, there have been changes in procedures since 2014 and there is more information out there but for general homebrewing (if you are not a fierce competition brewer), I think that we might be over-analyzing things.  I don't dispute your post, I am just thinking, RDWHAHB.  If your beer tastes good to you and your friends, all is good with the world.  If you start having oxidation problems, then it's time to take a look at your process.

I'm inclined to agree with you WRT the simple fact that if you enjoy the beer you make then over analyzing it is a solution in search of a problem.

If, however, we want to discuss how to structure a valid comparison between two beers that analyzes a single variable such as HSA at a certain point in the process, then you have to get in the weeds a little bit and make the distinction I did.

In general, the most devastating type of oxidation is on the cold side, but there is an incredible amount of nuance and degrees of damage on the hot side as well. It's just a matter of what you are trying to determine from an experimental point of view.

You are absolutely right though when you say that ultimately it's the individual brewer who has to decide when and where improvements are warranted.