How Do You Aerate?

[Qhrumphf]

The actual numbers depend on a multitude of variables, but above 8 PPM seems to be the generally accepted upper threshold. Without a way to measure dissolved O2 and adjust accordingly, it's kinda moot anyway.

My point is that it's not even possible to over-oxygenate using a splashing method, but you will almost certainly over-oxygenate every time when using a pure oxygen rig. With pure O2 and a stone, it is very easy to sail way past the ideal range (as someone's measured numbers showed earlier). Under-oxygenating is rarely an issue, and never is if you're pitching enough healthy yeast to begin with, especially if you're using dry yeast, and/or supplying an adequate lipid source.

Source please.

This flies directly in the face of info from Wyeast as well as JZ and Chris White's "Yeast" book.

 

[masonsjax]

Source please.

This flies directly in the face of info from Wyeast as well as JZ and Chris White's "Yeast" book.

Those guys say that over-oxygenation is not a problem because the yeast will use the excess oxygen within a few hours. This is true, but what they don't mention is that the yeast use it to create compounds we are generally trying to avoid in our beer. The levels of these off-flavors from this phenomenon are probably below the taste threshold of most people, but if you can achieve even incrementally better results without spending money on gear, it makes sense to me to not buy the gear.

I read a lot and don't keep track of every reference because I'm not writing research papers, this is just a hobby for me A quick Google search turns up this brief write-up on the role of oxygen in beer, which appears to touch on some of the concepts I've been running my mouth about.

http://www.morebeer.com/articles/oxygen_in_fermentation

 

[1975brewer]

I have been a home brewer for almost 40 years & until last year when I started using an aquarium pump, filter & stone I would sit with my plastic paddle & splash the wort all over the sides of the bucket. I didn't even make yeast starters until I found HBT about 3 years ago.

 

[sky4meplease]

White and Zainasheff state in the Yeast book that 8-10 ppm is the recommended O2 level and wort above 1.083 OG should get another blast of O2 12-18 hours into fermentation.
While they mention over oxygenation, they do not state what that number is only saying it is "rarely a problem". I would love to see a reference as to how many ppm of O2 is over oxygenated.
Additionally, the book states that extended aeration times using the agitation method is detrimental to head formation and retention.
On a side note, that experiment I ran a week and a half ago got dry hopped today and had attenuated from 1.058 to 1.010 fermenting at 62 degrees. That's 82.7 %. That wort had 14.31 ppm dissolved O2 before pitch. It tasted quite delicious if I do say so. I will be shortening up the duration that I pump O2 from 60 seconds to 30 seconds in the future and will post the results when they are available.

 

[Qhrumphf]

Those guys say that over-oxygenation is not a problem because the yeast will use the excess oxygen within a few hours. This is true, but what they don't mention is that the yeast use it to create compounds we are generally trying to avoid in our beer. The levels of these off-flavors from this phenomenon are probably below the taste threshold of most people, but if you can achieve even incrementally better results without spending money on gear, it makes sense to me to not buy the gear.

I read a lot and don't keep track of every reference because I'm not writing research papers, this is just a hobby for me A quick Google search turns up this brief write-up on the role of oxygen in beer, which appears to touch on some of the concepts I've been running my mouth about.

http://www.morebeer.com/articles/oxygen_in_fermentation

Interesting article, but it doesn't really cover anything that's not in the "Yeast" book, and in fact pretty much agrees with it, aside from the recommended threshold for DO of 8ppm as an upper limit instead of recommended 8-10 ppm. It does recommend a higher pitching rate (1 million cells vs 0.75 million cells per ml per °P), which would then jive with a decreased rate of aeration. Only thing I didn't recall being in there (and it may be) is the use of dead yeast and/or trub for a lipid source. Which is interesting. I suppose the takeaway is that if you do dump fresh wort onto a yeast cake, aerating is probably a bad plan.

What this article does say (as does the book) is that aeration/oxygen requirements may not be the same for every beer, and the same goes for pitching rates (not mentioned in the article but is in the book). So it's all about finding what works for you.

Still no real data on what levels become over oxygenated though.

And it does note that most homebrewers are underpitching. Interesting thing I hadn't considered until I was corrected- if your starter is even on a stir plate, if you're not getting substantial gas transfer into and out of your flask, your yeast will use up all the oxygen in the flask very rapidly and the stir plate becomes moot. Since most homebrewers aren't pumping air into the headspace of their starters (I know I wasn't), you may not be reaching the pitching rate you think you are.

 

[masaba]

Those guys say that over-oxygenation is not a problem because the yeast will use the excess oxygen within a few hours. This is true, but what they don't mention is that the yeast use it to create compounds we are generally trying to avoid in our beer. The levels of these off-flavors from this phenomenon are probably below the taste threshold of most people, but if you can achieve even incrementally better results without spending money on gear, it makes sense to me to not buy the gear.

I read a lot and don't keep track of every reference because I'm not writing research papers, this is just a hobby for me A quick Google search turns up this brief write-up on the role of oxygen in beer, which appears to touch on some of the concepts I've been running my mouth about.

http://www.morebeer.com/articles/oxygen_in_fermentation

Thanks for posting this. Looks like if you are pitching a nice healthy yeast culture all you need to do is pour through a strainer and shake for a minute or two to reach 8 ppm. I'm sure that using an O2 stone works well also.

 

[orangehero]

Mistake.

 

[Mexibilly]

Never had an issue, and always very good results.
If you're concerned I guess I'd suggest blowing your drill off thoroughly with compressed air.

 

[darylwoodman]

I shake the fermenter like my life depended on it. My brew neighbors enjoy the 45 second show as my veins pop out and I look like the clip of Arnold Schwarzenegger in Total Recall when his mask comes off in a zero atmosphere. It's painful, but feeding those little buggers is an essential job.

 

[FamilyTradition]

When my immersion wort chiller is doing it's thing I move it up and down in the brew pot real fast cools it a little quicker and adds a good amount of air

 

[russell58]

Started with shaking 2 gallon buckets moved to 5 gallon and after reading here brought aeration system pump , filter and stone.

 

[PackerfaninSanDiego]

I use a sanitized paint mixer and a drill. Never had a problem

ditto/////////

 

[FamilyTradition]

I shake the fermenter like my life depended on it. My brew neighbors enjoy the 45 second show as my veins pop out and I look like the clip of Arnold Schwarzenegger in Total Recall when his mask comes off in a zero atmosphere. It's painful, but feeding those little buggers is an essential job.

Haha used to clean my carboys this way, till one flew out of my hands looked like something out of a movie. Luckily it was a plastic Carboy. Nothing like going into hulk/beast mode to add oxygen

 

[jbb3]

I started out using that, but found that after just a few brews, it was rusting pretty badly. I switched to a "Fizz-X" wine de-gassing rod (stainless steel shaft with hard plastic arms) and it's worked great ever since.

I accidentally left my paint mixer attachment in a bucket of StarSan for several days. When I found it, the StarSan had stripped the chrome finish off the rod. Had to toss 5 gallons of StarSan solution and won't use that mixer attachment again.

Just looked up the Fizz-X and that looks like it would do the trick. Might have the trim the plastic arms a bit so it will fit down inside my IC while it's in the kettle.

 

[Dave_K]

When my immersion wort chiller is doing it's thing I move it up and down in the brew pot real fast cools it a little quicker and adds a good amount of air

Wouldn't this method potentially cause hot-side aeration if done before sufficiently cooled?


Also, to those using the disposable O2 tanks from the hardware store. Approximately how many 5 gallon batches will one tank aerate?

 

[FamilyTradition]

Wouldn't this method potentially cause hot-side aeration if done before sufficiently cooled?





Also, to those using the disposable O2 tanks from the hardware store. Approximately how many 5 gallon batches will one tank aerate?

I do it about the last few minutes, when my temp sensor is close to my target.

 

[masonsjax]

I believe hot side aeration is an old wives tale.

 

[Qhrumphf]

My understanding of HSA is that it's dwarfed by cold side. The oxygen uptake while racking properly would still dwarf anything you get from HSA. At least that's what I've garnerned from Charlie Bamforth talking about the subject.

IE don't worry about HSA.

 

[Dave_K]

My understanding of HSA is that it's dwarfed by cold side. The oxygen uptake while racking properly would still dwarf anything you get from HSA. At least that's what I've garnerned from Charlie Bamforth talking about the subject.

IE don't worry about HSA.

Good to know. I don't personally know anything about the issue of hot-side aeration or what damage it supposedly causes. I've just heard warnings of it numerous times.

I suppose I'll have to do some research in to it.

 

[Kampenken]

Wouldn't this method potentially cause hot-side aeration if done before sufficiently cooled?


Also, to those using the disposable O2 tanks from the hardware store. Approximately how many 5 gallon batches will one tank aerate?

I use the tanks, based on what I've used, I expect 10-15 5g batches, this is why I didn't bother investing in the large 20# tanks.

 

[jbb3]

Good to know. I don't personally know anything about the issue of hot-side aeration or what damage it supposedly causes. I've just heard warnings of it numerous times.

I suppose I'll have to do some research in to it.

So... just trying to make trouble aye??

 

[vincentAlpha]

I have a plastic scoop with holes through it, sanitize and stir/whisk to a nice froth after letting the wort drop a good foot. Doesn't take long and the last time I had activity in 3-4 hours.

 

[Dave_K]

So... just trying to make trouble aye??

Seemed like a reasonable question to me, but I'm not opposed to causing a little trouble every now and then

 

[Bobcatbrewing42]

I would skip the strainer or any other step that could contaminate the wort. I ferment in glass carboys. To me aeration is so simple that I don't need another gizmo to help. (there are lots of gizmos on my list, but not that- 20 gal conical fermenter?) I set my carboys on a rubber mat to keep from breaking and lean them onto one edge and agitate. It easily develops a couple of inches of foam on top. I use a sanitized rubber stopper with no hole to do this, then open it to let in more O2. I do it again after pitching. If it isn't broken...don't fix it.

 

[sky4meplease]

I may stop straining and try whirlpooling at some point now that I use O2 to oxygenate. I guess I have to weigh out the pros and cons of straining, aerating and pitching vs. waiting for the whirlpool, transferring, aerating and pitching.
Also, I don't think I will use O2 on every brew. I may skip it for certain styles or certain flavor profiles but I think it's a good tool to have in my arsenal.

 

[Kampenken]

Also, I don't think I will use O2 on every brew. I may skip it for certain styles or certain flavor profiles but I think it's a good tool to have in my arsenal.

Sky- Will your plan on skipping O2 be on lower OG beers? I just bottled a blonde ale and I "only" shot about 30-40 sec this time on a 1.048 OG. Probably didn't need that much. I am bothered by 87% apparent attenuation, low mash temp 150, 60 min mash, fine ground crush on my mill & a thinner mash than normally use (1.5 v 1.25) may all have contributed, as I'm hoping its not an infection, at bottling didn't taste like one. I don't feel I overpitched yeast, Denny's Fav 50 I did use a starter to hit Brewer's Friend rate, it was a slow, long fermentation (~6-7 days). I don't think my O2 contributed but am wondering if you too would avoid on low OG beers, or what is the style you'd avoid O2?

 

[sky4meplease]

My choice to not oxygenate wort wouldn't likely be based on OG but more for ester production or fusel alcohols levels. Increasing O2 will reduce ester production and increase fusel alcohol levels.
For styles that benefit from ester production you could raise the fermentation temperatures, deliberately under pitch yeast (risky and most Brewers probably already do it unknowingly anyway) or under oxygenate your wort to facilitate ester production.
When I started using O2 my lagers mysteriously stopped getting real estery.
I mainly brew styles that call for low ester levels so I oxygenate for 20-30 seconds and have been reaching 10-15 ppm in 5.5 gallons of wort. I try not to get higher than that because I don't want a real fusel bomb either.
For styles like Dunkelweizen that call for a strong prominent ester profile high O2 levels may be counter productive. Check the BJCP style guidelines for ester and alcohol level guidance in traditional styles or decide which levels fit your taste and make educated decisions about how much if any O2 to add to your wort. Keep in mind that low O2 levels in wort can impact yeast health in future generations if harvesting.
As for your Blonde Ale, I don't think 87% attenuation is out of line for a low flocculating yeast like Denny's especially with your low mash temp. Your well oxygenated wort probably helped get you there but I routinely plan on getting 80+% attenuation when mashing at low temps. I normally figure the average attenuation given by the manufacturer is for the middle of the mash range (153 degrees based on a range of 148-158 degrees) and adjust my target mash temp accordingly. For example, for a yeast with an average attenuation of 74% I may plan on getting 88% if mashed at 148 and 66% if mashed at 158 assuming my fermentation temps are in the middle of the ideal range. To elaborate a little more on FG's I may do a mash out if I am shooting for a high FG (low attenuation) or wait to bring my wort to 160+ degrees until after I have my pre boil volume if I'm looking for a low target FG (high attenuation).
I wouldn't worry too much about over pitching or mash thickness though there are some considerations to be given there.
As for your crush, I would shoot for efficiencies in the mid to upper 70's and strive for consistency but I don't think it played a major role in your attenuation levels.
I hope this helped.