A Stubborn Old Brewer?

A long-time brewer friend of mine was helping analyze my first brew (standard extract + steeped grain kit: American Amber) and suggested some unusual things (contradictory to things I've read on here).

First, he said his main comment on my brew was that it lacked body. He suggested this might be from letting the fermentation go too long (too dry), and/or from topping-off to go from 3-gal boil to 5-gal batch. He says that this topping-off isn't good, and waters down the beer (of course it does), even though it is extract, and PART of the recipe itself!.

Not sure about the over-fermented part. I got the impression extra time in primary wasn't generally a bad thing. It fermented in primary from 1.060 to 1.016 (matched the recipe) in 2 weeks). Its been in bottles for a month+.

Second, he says when he racks to bottling bucket, he tries to aerate the beer! He stirs the beer in the bucket until it is frothy!! I presume this is anticipation of more yeast activity on the priming sugar, but everything I've read says after pitching/aerating, that you want to forever avoid further aeration.

He admits that this is partly 'how he's done it for 10 years', and implied he would just keep doing so. He has a background in biology & science, so he understands the concepts involved. If I know his methods are wrong, he'd listen, but I wasn't equipped to dispute it without consulting the experts here. Are these techniques that have changed drastically since he started brewing?

Thanks
Aaron

I've read on this board that there are 10 times more yeast in solution than necessary to carbonate a beer. There is absolutely no need to provide more oxygen to them before bottling. Some people say that oxygenated beer tastes like "sherry", so if that's the flavor he likes then go for it, I guess.

Additional time will decrease certain by-products, especially diacetyl. If he wants that flavor then excessive primary will deprive him of it. It's true that dry beers don't have body, but length of time in the primary isn't what tends to make a beer dry -- it's your choice (and quantity) of fermentables, as well as your yeast's ability to digest those fermentables.

greenfrog5 said:

A long-time brewer friend of mine was helping analyze my first brew (standard extract + steeped grain kit: American Amber) and suggested some unusual things (contradictory to things I've read on here).

First, he said his main comment on my brew was that it lacked body. He suggested this might be from letting the fermentation go too long (too dry), and/or from topping-off to go from 3-gal boil to 5-gal batch. He says that this topping-off isn't good, and waters down the beer (of course it does), even though it is extract, and PART of the recipe itself!.

Not sure about the over-fermented part. I got the impression extra time in primary wasn't generally a bad thing. It fermented in primary from 1.060 to 1.016 (matched the recipe) in 2 weeks). Its been in bottles for a month+.

Second, he says when he racks to bottling bucket, he tries to aerate the beer! He stirs the beer in the bucket until it is frothy!! I presume this is anticipation of more yeast activity on the priming sugar, but everything I've read says after pitching/aerating, that you want to forever avoid further aeration.

He admits that this is partly 'how he's done it for 10 years', and implied he would just keep doing so. He has a background in biology & science, so he understands the concepts involved. If I know his methods are wrong, he'd listen, but I wasn't equipped to dispute it without consulting the experts here. Are these techniques that have changed drastically since he started brewing?

Thanks
Aaron

Click to expand...

I think your friend needs to read a brewing book. Having a degree in biology dosen't make somebody a brewer anymore than having a degree in geology makes you a stone mason.

greenfrog5 said:

First, he said his main comment on my brew was that it lacked body. He suggested this might be from letting the fermentation go too long (too dry), and/or from topping-off to go from 3-gal boil to 5-gal batch. He says that this topping-off isn't good, and waters down the beer (of course it does), even though it is extract, and PART of the recipe itself!.

Click to expand...

Your friend probably always does full boils, not partial boils. Full boils allow better hop utilization, which isn't "body", but is important.

Question - was this a style of beer your friend likes/brews? For instance, if you brewed an APA and your friend likes English porters, you are comparing apples to oranges...

My question would be:

How does your beer taste to YOU??

Take his comments for what they are - HIS OPINIONS.

Dont let anyone make your brewing decisions for you. Find your own path.

Yeast undergo cellular respiration just like we do:

(6) O2 + Glucose (C6H12O6) = (6) CO2 + (6) H20. And aerating the wort at priming sugar time does energize the yeast.

However, once the O2 is gone, the yeast undergo anaerobic respiration just like we do when we exercise - but we create lactic acid which makes our muscles sore. Yeast create EtOH (ethanol or alcohol). This is why you want to aerate your wort prior to pitching yeast but you DON'T want to expose your brew to oxygen during the fermentation phase (no anaerobic respiration occurs thus little or no alcohol is formed and your wort oxidizes! Bleah!)

At priming sugar/bottling time: I too, aerate the wort again with my Braun "boat motor" (as Emeril Lagasse calls it) when I prime with sugar.

Don't worry - the yeast will wake up to gobble up all the oxygen AND the glucose to create the fizz in your bottles. Isn't Mother Nature wonderful?

As for the taste of your brew: it's all in the eye of the beholder. If you dig it, then that's all that matters.

damnyankee said:

At priming sugar/bottling time: I too, aerate the wort again with my Braun "boat motor" (as Emeril Lagasse calls it) when I prime with sugar.

Click to expand...

I'm curious, how long do you age your beer in the bottles?

So basically he likes green beer that tastes like liquid cardboard? I didn't know for one thing that oxydized beer had great body...Who would have thunk it.

The length in primary idea, has changed with time, and many of us have argued your beer is improved by more yeast contact. The yeast can clean up after itself.

Here's where all the latest info you can find on this is. https://www.homebrewtalk.com/f163/s...amil-zainasheff-weigh-176837/?highlight=jamil

Whipping his beer into a froth at bottling time = Oxydized Beer....One of the worst pieces of brewing advice I have ever seen/heard.

From How to brew.

2a. If you have a bottling bucket (see Figure 66) gently pour the priming solution into it. Using a sanitized siphon, transfer the beer into the sanitized bottling bucket. Place the outlet beneath the surface of the priming solution. Do not allow the beer to splash because you don't want to add oxygen to your beer at this point. Keep the intake end of the racking tube an inch off the bottom of the fermenter to leave the yeast and sediment behind.

Click to expand...

From "Beer Brewing and Dissolved Oxygen" http://www.eutechinst.com/tips/do/09_DO_beer_brewing.pdf

Oxygenation: When and How Much?
Before it all begins: Pre-fermentation
Oxygen is introduced to the wort after boiling, and prior to the addition of yeast. ... the oxygenation process should take place before, not after fermentation has commenced. As fermentation progresses towards completion, oxygen uptake is reduced, and any additional oxygen injected into the wort will not be used off. Instead, it remains to react with other compounds in the beer, creating staleness and undesirable tastes.

...Oxygen control after the beer is brewed
At the end of fermentation, the beer is completely free of oxygen. At this point, the beer is highly susceptible to oxidation, which has the following effects on the end-product:
- Undesirable taste
- Cloudy/ hazy beer
- Increased beer astringency
- Darkened beer colour
There are several ways to prevent oxidation of the beer after fermentation, one of which is to blanket tanks with inert gases. Use only de-aerated water for dilutions, as well as to run through beer transfers, and keep the finished product in cool storage during the supply chain.

Click to expand...

From BYO magazine. http://***********/stories/techniques/article/indices/7-aeration/1949-aerating-wort-techniques

Oxygen in beer is undesirable except at one point (and only one point) in the brewing process. That lone point is when the post-boil wort has been chilled down to fermentation temperature, but before the yeast has been pitched into it.

Click to expand...

Doesn't say anything about "However during bottling you need to/can introduce more oxygen." Instead it says, Oxygen after fermentation is bad. That simple.

There's not enough fermentation in the bottle to fix oxydized beer. You are talking a tiny bit of sugar being fermented, barely enough to raise the gravity by what .003 points? You guys actually believe that's going to matter to 5 gallons of cardboard???

If that were the case there would be know oxydyzed beers in bottles showing up in contests, ask ANY bjcp judges if they've ever tastest oxydized beers in contests, and I think you'll put that silly notion to rest. Come on, what lunacy, we tell brewers to AVOID too much O2 exposure to fermented beer, only to have folks make beer meringue?

The reason he doesn't like your beer, isn't because you've done anything wrong, or your process sucks it's because he's been making ****ty beer for the last decade and his taste buds are used to it. He wouldn't know good, unoxydized beer if it bit him in the a$$.

Are you brewing beer for him and to please his opinion or are you brewing beer for yourself?

It's always good to seek the opinions of others who may give you some insight into what you've made. But the thing to keep in mind is that while they may make suggestions the ones you should take into consideration are those that appeal to your own tastes.

If his tastes and yours coincide then great!

If not....eh....nice to know that others have opinions.

A friend brewer I know pronounced one of my Stouts "undrinkable" once. I took offense for a few seconds until I realized that he almost exclusively brewed nothing but lighter Ales.

Skarekrough said:

A friend brewer I know pronounced one of my Stouts "undrinkable" once. I took offense for a few seconds until I realized that he almost exclusively brewed nothing but lighter Ales.

Click to expand...

Opposite thing happened to me once. I brewed a Munton's kit, pronounced it "undrinkable"... but one of my co-workers thought it was the best damned beer he'd had in his life.

Diff'rent Strokes! :fro:

The reason he doesn't like your beer, isn't because you've done anything wrong, or your process sucks it's because he's been making ****ty beer for the last decade and his taste buds are used to it. He wouldn't know good, unoxydized beer if it bit him in the a$$.

Click to expand...

There's something to that. For years, a friend and I brewed and let it ferment in what was basically a garage. During the summer, we got some pretty good fermentation action, think volcano. We actually did brew some pretty decent beer, and some of our offerings placed in competiton. Subtlety, nuance, and hint of flavor were not descriptions we used. I agree with the comments the other brewers here have made. Especially the one about if you like it, that's all that matters. - Dwain

Justibone said:

I'm curious, how long do you age your beer in the bottles?

Click to expand...

I plan on several weeks. Now, I don't go nuts and aerate as I do with the original wort prior to fermentation, but I do give a several whirls with my boat motor after I've added my priming sugar.

Rational: I like fizz in my beer. I want to introduce a little O2 with the priming sugar into the solution so the yeast starts aerobically producing CO2 (the partial pressure between the two gases will equal out). BUT I don't want to introduce too much O2 because if the yeast consumes the glucose before O2, the solution will oxidize. Once anaerobic respiration begins, I'll get more CO2 in addition to the little extra CO2 I added from the aerobic stage. I hope that makes sense.

Now, last week when I tasted my Blue Moon clone post Bottle Day 6, it already developed a nice fizz and head; and for a young beer, it tasted great. Was I lucky? Maybe. But scientifically speaking, adding a little O2 after the priming sugar and before bottling should kick up the fizz a bit. It's all a personal preference.

Lack of body might be a legitimate comment; however it isn't due to "watering down" to the recipe-specified volume OR over-attenuation. Your attenuation isn't excessive. More likely the beer just needs to age a bit and finish carbonating. If you aren't satisfied with the body and mouthfeel then, adding 4-8 oz of maltodextrin is the best method for an extract brewer.

If you haven't been to the Oak Barrel, you should visit them. They were very helpful when I started brewing.

Won't add anything to the comments on oxygenating beer before bottling, except to say I'd never do it either.

Look, you weren't supposed to come on here and tell everyone what I said!! Thanks a lot...

damnyankee said:

But scientifically speaking, adding a little O2 after the priming sugar and before bottling should kick up the fizz a bit. It's all a personal preference.

Click to expand...

Hmm....

Fermentation CO2: C6H12O6 → 2C2H5OH + 2CO2
Respiration CO2: C6H12O6 + 6 O2 → 6 CO2 + 6 H2O

Given the same amount of fuel, you'll get 3 times more gas if you oxygenate your beer before bottle carbing, theoretically. You raise an interesting point: oxygenating beer could potentially also contribute to "bottle bombs".... hmmmmmm...

Of course, you could just add extra fuel, and if you want your bottles carbed extra fast then you could just add more yeast (bottle some of the cake in there).

I guess that what you're doing has solid scientific underpinnings, I just don't personally think it's worth the risk of oxidation to save on some sugar and get slightly less alcohol from the secondary fermentation. That's my unsolicited advice!

damnyankee said:

Rational: I like fizz in my beer.

Click to expand...

Just a question, but couldn't you just adjust the priming sugar up (use more) at bottling to reach the upper end of the carbonation level for the style, or to whatever your preference is in terms of carbonation, vs. risking oxidation by stirring it like you describe?

mr_bell said:

Just a question, but couldn't you just adjust the priming sugar up (use more) at bottling to reach the upper end of the carbonation level for the style, or to whatever your preference is in terms of carbonation, vs. risking oxidation by stirring it like you describe?

Click to expand...

That's what you're supposed to do. It's called "carbing to style." It's the most common way of controlling "fizz." Not making liquid cardboard....

mr_bell said:

Just a question, but couldn't you just adjust the priming sugar up (use more) at bottling to reach the upper end of the carbonation level for the style, or to whatever your preference is in terms of carbonation, vs. risking oxidation by stirring it like you describe?

Click to expand...

Absolutely! But I don't need to tell you when extra sugar is added in an anaerobic environment, you'll generate both CO2 AND EtOH content...and the additional EtOH may augment the flavor of the beer in a good or bad way. Plus, there's the risk of bottle grenades.

To create more fizz (as I like), it's all a very delicate balance either way ya go...I think a few whirls of the boat motor in an aerobic environment to introduce a little extra O2 to create a little extra CO2 fizz may have has less risk in creating bottle grenades.

I'll let you know in a few weeks as my bottles continue to ferment. Who knows...maybe it'll make bottle grenades or there'll be TOO much fizz and the brew becomes too champagne-like. We'll find out! Gee, isn't Chemistry fun?!!!

Take care All!

DY

The extra EtOH is not very significant, flavor-wise, compared to oxidation.

If you have enough oxygen to eat all of the sugar aerobically, then you could use 1/3rd the sugar to get the same carbonation. I assume your oxygenation is incomplete, based on what you said, and so I also assume you don't use 1/3rd the recommended sugar.

You're free to do what you like, it's your beer... but I wouldn't do it or encourage others to do it.

Justibone said:

Opposite thing happened to me once. I brewed a Munton's kit, pronounced it "undrinkable"... but one of my co-workers thought it was the best damned beer he'd had in his life.

Diff'rent Strokes! :fro:

Click to expand...

Similar thing happened in my last batch. I tried it and was not very fond of it. Drinkable, but I didn't like it much. Everyone else seems to love it. Granted, it's gotten a better having aged some more.

I'm siding with thousands of years of experience here. If aerating at the bottling stage was the 'better' way to go, ALOT more of us would be doing it by now. Not saying it can't be done, but, the risk seems greater than the reward. Maybe some day somebody will come up with a safe/dependable way to do it. To each their own, but I'm not going to be doing it any time soon.

iron_city_ap said:

I'm siding with thousands of years of experience here. If aerating at the bottling stage was the 'better' way to go, ALOT more of us would be doing it by now. Not saying it can't be done, but, the risk seems greater than the reward. Maybe some day somebody will come up with a safe/dependable way to do it. To each their own, but I'm not going to be doing it any time soon.

Click to expand...

Let's circle this conversation back around to what the Stubborn Old Brewer stated about his aerating prior to bottling. Biochemically, the "SOB" is correct AS LONG AS there's adequate sugar available for the yeast.

It's just a different way of looking at yeast fermentation.

DY

Like I said, I don't doubt that it can be done, but to me the risk is greater than the reward. Biochemically, I'm sure there is alot you can do to beer, but that doesn't mean it will taste good. If you want to do it, I'm not about to tell you not to. Its just not for me.

iron_city_ap said:

like i said, i don't doubt that it can be done, but to me the risk is greater than the reward. Biochemically, i'm sure there is alot you can do to beer, but that doesn't mean it will taste good. If you want to do it, i'm not about to tell you not to. Its just not for me.

Click to expand...

+1,000

It seems to me that while it could work, aeration at bottling time to increase carbonation seems like it would be unpredictable at best. How can you quantify the amount of O2 you're adding to the solution, and do it reliably with repeat batches? Too many variables for me. Adding extra sugar and yeast gives you the same effect with the benefit of consistency and without the risk of wet carboard. But hey, if it works for you, knock yourself out.

To the OP: the old guy's stuck in old ways and doesn't want to learn new tricks.

"How can you quantify the amount of O2...?"

That right there is the million dollar question. I've been thinking about this from both a biochemical and financial perspective. It makes me wonder if there's a undiscovered family of beverages with a combination of aerobic fermentation quantified with specific subsets of oxygen and glucose infusions combined with anaerobic fermentation...? Maybe an additional step after anaerobic fermentation is needed to remove the cardboard flavor?

Centuries ago, the first brewer who shared a thought about distilling his good beer & wine probably was ridiculed by his peers...and after he perfected the procedure, we know the rest of that story...

Anyway, back to my kettle...

DY

Oxygenating fermented beer has a number of flavor components. If your beer is particularly hoppy it will accelerate oxidation of the hop oils which will make your beer taste cheesy/vomity over time. Oxygen also oxidizes the beer, which lends to a cardboard taste. Also, adding oxygen to fermented beer increases exposure to wild, oxidative yeast like candida and brett which can infect the beer and increase the cardboard taste (in the case of candida) or funky/barnyard flavors (in the case of brett).

I don't really see the upside there.

ReverseApacheMaster said:

Oxygenating fermented beer has a number of flavor components. If your beer is particularly hoppy it will accelerate oxidation of the hop oils which will make your beer taste cheesy/vomity over time. Oxygen also oxidizes the beer, which lends to a cardboard taste. Also, adding oxygen to fermented beer increases exposure to wild, oxidative yeast like candida and brett which can infect the beer and increase the cardboard taste (in the case of candida) or funky/barnyard flavors (in the case of brett).

I don't really see the upside there.

Click to expand...

What, you don't like moldy barnyard cheese-covered cardboard? What's your problem?

LOL

TheDom said:

It seems to me that while it could work, aeration at bottling time to increase carbonation seems like it would be unpredictable at best. How can you quantify the amount of O2 you're adding to the solution, and do it reliably with repeat batches? Too many variables for me. Adding extra sugar and yeast gives you the same effect with the benefit of consistency and without the risk of wet carboard. But hey, if it works for you, knock yourself out.

To the OP: the old guy's stuck in old ways and doesn't want to learn new tricks.

Click to expand...

I think people are confusing aeration and stirring. They aren't the same thing. Stirring/swirling to distribute the priming sugar throughout the solution at bottling isn't the same as beating the liquid and injecting oxygen into it.

BigEd said:

I think your friend needs to read a brewing book. Having a degree in biology dosen't make somebody a brewer anymore than having a degree in geology makes you a stone mason.

Click to expand...

I can actually attest to this. I have a geology degree and sucked at helping my friends to build a stone wall around their garden.

This guy sounds like he learned some incorrect methods and is unwittingly propagating them on to you. Body is the result of unfermentable sugars. No matter how long you wait in the primary that isn't going to change.

ReverseApacheMaster said:

Oxygenating fermented beer has a number of flavor components. If your beer is particularly hoppy it will accelerate oxidation of the hop oils which will make your beer taste cheesy/vomity over time. Oxygen also oxidizes the beer, which lends to a cardboard taste. Also, adding oxygen to fermented beer increases exposure to wild, oxidative yeast like candida and brett which can infect the beer and increase the cardboard taste (in the case of candida) or funky/barnyard flavors (in the case of brett).

I don't really see the upside there.

Click to expand...

If we can think beyond the Medieval methods of brewing for one moment, here's the hypothetical upside:

As yeast prefer aerobic environments:

yeast use (6) O2 + C6H12O6 (glucose) to produce (6) CO2 + (6) H20. There are no other byproducts (good or bad) or metabolites in that chemical reaction.

A carefully controlled infusion of a 6:1 ratio of O2 & glucose (priming sugar) into the wort just prior to bottling SHOULD (on paper) theoretically speed up bottle conditioning 6-fold. And since CO2 is a weak acid and it's loaded up quickly right after bottling, the CO2 should help "mellow" the beer sooner.

On paper, this means you could be drinking your fine brew in mere days instead of weeks.

Again: the key to aerobic fermentation is to ensure there is ample sugar with the oxygen for the yeast to munch on. If sugar is used up before the partial pressure of O2 in the wort, then the game is over: the O2 will be broken down and oxidized in the wort.

On paper, it works. Man, if I only had access to a chemistry lab with a pressurized system to keep O2 & CO2 in solution to see if Mother Nature behaves as predicted on paper...

DY

damnyankee said:

On paper, it works. Man, if I only had access to a chemistry lab with a pressurized system to keep O2 & CO2 in solution to see if Mother Nature behaves as predicted on paper...

Click to expand...

and that, right there, is probably why you don't hear of this in the homebrew community. Possible in theory doesn't equal practical or actual. The other thing that confuses me, is the talk of 6:1 ratios and chemistry labs and whatnot, yet "Now, I don't go nuts and aerate as I do with the original wort prior to fermentation, but I do give a several whirls with my boat motor after I've added my priming sugar.
. Your theory and what you actually do seem far apart.

Its like the old 'measure it with a micrometer, mark it with a grease pen, and cut it with an axe' adage.

If you can prove the theory works and can find a way to make it practical and affordable for the rest of us, by all means, go for it.

damnyankee said:

If we can think beyond the Medieval methods of brewing for one moment, here's the hypothetical upside:

As yeast prefer aerobic environments:

yeast use (6) O2 + C6H12O6 (glucose) to produce (6) CO2 + (6) H20. There are no other byproducts (good or bad) or metabolites in that chemical reaction.

Click to expand...

Unless you are mixing in pure O2 you are also introducing whatever is kicking it in the air around you, which includes bacteria, mold spores, oxidative yeast, etc. which also will make their home in the beer. Even assuming the O2 is consumed before it can oxidize the beer and make it taste like cardboard over time the other critters you have invited into your beer over time can break down unfermentable sugars and develop other off flavors.

A carefully controlled infusion of a 6:1 ratio of O2 & glucose (priming sugar) into the wort just prior to bottling SHOULD (on paper) theoretically speed up bottle conditioning 6-fold. And since CO2 is a weak acid and it's loaded up quickly right after bottling, the CO2 should help "mellow" the beer sooner.

On paper, this means you could be drinking your fine brew in mere days instead of weeks.

Click to expand...

The CO2 doesn't mellow the beer nearly as much as the yeast doing their clean up work affects cleaning up the green beer flavors. Granted, people force carb beer and drink it within days, I bet the beer still tastes better after weeks rather than days. Additionally, even without the contribution of oxygen beer can carbonate within days through the normal bottle conditioning process. It will still taste green.

Again: the key to aerobic fermentation is to ensure there is ample sugar with the oxygen for the yeast to munch on. If sugar is used up before the partial pressure of O2 in the wort, then the game is over: the O2 will be broken down and oxidized in the wort.

On paper, it works. Man, if I only had access to a chemistry lab with a pressurized system to keep O2 & CO2 in solution to see if Mother Nature behaves as predicted on paper...

DY

Click to expand...

And like iron city said, that theory and what you do in practice are totally different...

damnyankee said:

If we can think beyond the Medieval methods of brewing for one moment, here's the hypothetical upside:

As yeast prefer aerobic environments:

yeast use (6) O2 + C6H12O6 (glucose) to produce (6) CO2 + (6) H20. There are no other byproducts (good or bad) or metabolites in that chemical reaction.

Click to expand...

While all that is true, you're focusing on one tree in an entire forest of chemical reactions that make up cellular respiration in the yeast. It seems like you're trying to say that in an aerobic environment yeast produce nothing but CO2 and H20, which is certainly not the case. If you're not saying that, my bad.

Again: the key to aerobic respiration is to ensure there is ample sugar with the oxygen for the yeast to munch on. If sugar is used up before the partial pressure of O2 in the wort, then the game is over: the O2 will be broken down and oxidized in the wort.

Click to expand...

Fixed that for ya. There is no such thing as aerobic fermentation. Fermentation implies anaerobic conditions.

Aerobic fermentation and aerobic respiration are two different processes. Aerobic fermentation was demonstrated over 50+ years ago. I guess metaphorically there's no sense of saying the world is round when it's flat - despite evidence to the contrary:

http://www.ncbi.nlm.nih.gov/pubmed/20958338

http://onlinelibrary.wiley.com/doi/10.1111/j.1472-765X.2010.02941.x/abstract <--cut/paste the URL to your browser

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2195284/

Since aerobic fermentation - particularly of yeast - doesn't exist, we should inform all the scientists who are slaving in their labs right now to stop their research in their respective fields - including Medicine and cancer research. Even though I earned a dual major chemistry and biology degree with a minor in Microbiology before entering medical school, I thought I had a solid command of these basic terms and their concepts but obviously I don't.

Since world is still flat, let's go back to our medieval way of brewing beer and stop talking about all this silly Mother Nature nonsense of speeding up bottle conditioning, shall we?

Wow, learn something new every day I guess. I'm calling UF's microbio department and asking for some of my money back. Although in their defense they were huge on anaerobes at the time, especially methanogens.

Maybe a new thread in the Brew Science section is in order? This whole thing has gotten a bit off topic methinks.

It's all good. I think we stayed on topic...the "SOB" was being dissed a bit for aerating at priming sugar time; he has a valid a scientific rationale (paper-wise) supporting the procedure. I calc'ed out the maximum amount of O2 in grams which can be dissolved in wort solution with 4 ounces of priming sugar and that total is 123 grams (using 100% O2) per 5 gallon carboy.

This is explains why wort can withstand an occasional popping of the lid to check SG's, some stirring, and a little aeration at priming sugar time to maximize carbonization without oxidizing the wort. So ease your oxidizing fears when you do your SG checks.

Now, let's get back to our cauldrons, shall we?

There is more going on in secondary (bottling) fermentation than just the production of CO2. I'm not convinced that oxygen dosing would enable all the flavor-enhancing processes to complete in only two days. It's too bad you went to med school instead of UCSF's (or wherever that is in CA) brewing PhD course.

Of course brewers are a very traditional lot by nature, so even if you did discover a different/faster way to do it, don't expect to be embraced.

See, that's the thing: noone knows. It's not just oxygen dosing, it's about using yeast in their preferred environment (aerobic fermentation) so they can produce massive amounts of CO2 (an acid) right away so that acid would start breaking down/maturing/age (whatever you want to call it) the wort right away instead of a period of days/weeks.

This is heresy in here to say but aerobic fermentation DOES happen in your primary BEFORE anaerobic fermentation occurs...all I'm postulating is there may be a way to manipulate the aerobic fermentation to our advantage.

I digress and am signing off the topic!

Cheers!