Is oxygenating with pure O2 better than shaking?

Contributor Greg compared oxygenating with pure O2 vs shaking in a split batch of the same wort!

http://brulosophy.com/2015/07/13/wort-aeration-pt-2-shaken-vs-pure-oxygen-exbeeriment-results/

 

Good stuff. I assumed that would be the results. I do agree it may make a difference with higher gravity wort and that's why I only use my oxygenation system on higher gravity brews, which isn't very often. The other times I use the "pour between two buckets from a high height" method.

 

Anecdotal, but I made a 1.092 Imperial Stout last year using my normal method (no O2 or shaking, just a little wort spray aerator) and it attenuated fully in 5 days after pitching a starter of 090. I'm not convinced pure O2 is ever necessary on the homebrew scale, though I suppose it offers some assurance.

 

The problem I have with shaking or pouring/splashing is that you introduce outside contaminants into your wort. Sure you might not notice a low level infection, but it's possible and after several months it may become more noticeable.

The second issue I have is that it's not repeatable. I use 1.5 lpm for 1 minute and I get consistent results.

 

I read this and while it was interesting, I wasn't very impressed with this particular xBmt. Partly because oxygenation is less important when using dry yeast and partly because there was no tracking of the fermentation other than looking at the bubbles from the blowoff tubes.

After recently getting an O2 system I have to say that I think it's worth it. I'm not too interested in the faster starts to fermentation, but my FG seems to be a point or two lower than before for similar recipes. Also, I do like reaching FG quicker and knowing that my yeast is nice and healthy if I want to repitch. I've only done two batches with the O2 but the viability of freshly harvested yeast has gone up from ~85 % to ~97 % using alkaline methylene blue staining.

 

Good point about being repeatable. That's another reason I moved to O2.

I also think having proper levels of DO is more important for lagers. Some of my lagers done with shaking for aeration were too estery and suffered from sluggish fermentations.

 

Gives more credence to the "pitch healthy vital yeast from a starter" mantra. It would unfortunately add another variable which would mess with the experiment, but pitching directly from a vial/smack pack into a pure O2/shaking I bet we would see the really big differences.

Edit: I don't use O2, I have a spigot on my kettle that points straight down so I just put that on my work bench and open it up, 3 feet of drop into the fermenter, steady pee-stream of wort. It's repeatable so long as the batch size is always the same (its always pouring from the same height, at the same rate) I always get 4-7% more attenuation than the yeasts advertised average (pitching a healthy starter).

 

I was considering the need for a pure oxygen aeration system as I was getting ready to brew a five gallon tripel, estimated OG 1.077 with WY3787. Worried I would have a FG in the upper teens.

Day 16 the SG was 1.013. Seems like a good end point for a tripel. Sample tasted good, still a little boozy though. Check SG again in a couple of more weeks.

So now I'm wondering, or confusing myself, if an oxygen set up would only be needed for wort over 1.080.

 

I would suspect it help more with certain strains than others.
So many variables. If surely benefits some and never hurts any...

 

You can't please all the people all the time. Some xBmts are naturally going to be a little less interesting than others, I still see the value in doing them. Not to sound defensive, I appreciate your feedback!

One thing- the fact you just bought an O2 setup arguably biases your perspective on whether it's worth it or not, which is only natural!

This is Greg's concern as well, hence he'll continue using pure O2 for his beers. I've brewed nearly 800 batches, never once used O2, many the same recipe with harvested yeast, and my consistency is pretty damn good.

 

I love your experiments. However, I, too, have heard that dry yeast does not require oxygenation of the wort. Perhaps you should try the same experiment with a liquid yeast.

I usually use O2, but made a 1.052 OG IPA over the weekend using SAFALE 04 and totally forgot to even shake the wort before I pitched the yeast at 64 degrees (I had too much on my schedule over the weekend and was lucky to be able to brew at all). I had 5 1/2 gallons of wort and used 2 re-hydrated packs of 04. 12 hours later, it was already bubbling away. While that's not the hole story obviously, the failure to aerate did not delay the start of fermentation at all. We'll see how it comes out. Keep up the great work! I love reading your blog.

 

I would argue that shaking/splashing is more consistent than pure O2 because if you shake/splash for 30 seconds to a minute (or more), you are always going to hit the saturation point for O2 in wort ~8ppm, or at least be very close. If you use pure O2, there is no upper limit. So, if you go 10 seconds over, or open up your valve a bit more or less, you could end up with different levels of O2.

On the contamination argument…I have always heard that the main sources of contamination are tubing, valves, or any other object with hard to clean surfaces. The process of shaking a carboy seems very unlikely to introduce significant sanitation issues. I would think that sticking an O2 wand into your cool wort is just as likely to introduce contamination as shaking.

 

04 is a beast. I'm pretty sure it would ferment dry concrete. Lol! A wort with an og of 52 would have fermented completely with only one pack of 04 rather quickly. I've never experienced a long lag time with 04 either. Like I said, 04 is a beast! Very efficient. Probably not a good strain to use as an example. Maybe some "yeast experts" here know a strain that highly relies on a strong concentration of o2. Then try a batch with o2 infusion and one with shaking/long pour and see the difference. For normal homebrewing, using pure oxygen is not really necessary... imo.


With all that said, I do long pour all my worts into the fermenter, and only use o2 on wort over 80... depending on the type of beer I'm shooting for. I do question the necessity of it though, but habits are hard to break.

 

I use a regulator/flow meter for my O2.

For the contamination issue, I'd disagree. Like I said it may only be a low level infection, but there will be contaminants in the wort. Especially if you crush grains anywhere near you brewing environment.

I always ask myself, would a professional brewer do this. If the answer is no and the price is within reason, then why wouldn't I do it the professional way. It costs < $40 for a O2 setup. Why risk it for the cost of a batch of beer.

 

+1. There are two questions at play:

(1) How do the dissolved oxygen levels compare? For this you really need a meter (here's one for $169). If they're similar, there's no reason to do a triangle test.

(2) If the dissolved O2 levels are significantly different, then what does the triangle test tell us?

For the Pure-O2 batch, we have no idea of flow rate or dissolved O2, so we can't say if the xBmt applies to our own processes.

 

Well the question is more, is it worth it to spend the money on a pure O2 system. It wasn't necessarily setting out to say if one or the other was "better".

If you can achieve *statistically* similar results while spending less money, which the xBmt showed, then its telling the people who brew on a budget or are just plain cheap-skates (me) we can get away just fine without buying a pure O2 system.

If the xBmt turned out that *statistically* people could tell the difference *AND* prefered the beer with pure O2, then that shows spending the money on an O2 system is worth it.

The xBmt doesn't really go into "pure O2 beers vs. shaking method beers, which one wins more medals at competitions". You would have to submit hundred and hundreds, probably thousands, of entries to get statistics of any use.

Edit: Yes, using dry yeast calls it into question a bit, since they will have all the sterols needed for reproduction, and its a relatively low gravity wort. I would like to see the xBmt repeated with liquid yeast in a starter, a starter that was shaken rather than placed on a stir plate. As a value based experiment it did show that at least if you use exclusively dry yeast, you should get fairly similar results regardless of spedning money on an O2 system.

 

I don't think that logic follows. Perhaps BOTH beers were under-aerated, resulting in some similar fermentation problems.

Depending on the O2 flow rate, you may need to run the O2 for anywhere from 1 to 10 minutes. So 2 mins certainly could be insufficient, who knows?

 

I guess to me the experiment wasn't getting into the minutae of dissolved oxygen content, theres plenty of other experiments out there that show how much dissolved oxygen you get over certain periods of time to show what is and isnt in the wort. I don't have the article right now but even with 30 minutes of intense shaking you cannot equal 1 minute of pure O2, so its doubtful that the pure O2 was "under" oxygenated.

Yes, the dry yeast is a problem. But the point is, you don't need to buy a pure O2 system to make good beer.

I think that with big starters of fresh healthy yeast no matter what we did with the 02, hell do 3 batches side by side. One pure O2 with well tracked flow rate, one batch oxygenated with 15 minutes of shaking, and one batch transfered slowly and carefully with a racking cane to prevent any splashing. I'd bet with big health starters and relatively low-medium gravity beers they would all come out tasting fine without major off flavors, the only one I could see anyone being able to pick out is the one with no oxygenation. Big healthy *vital* starter of yeast alleviates a lot of the issues arising from bad oxygenation. AKA I'd bet that if the experiment was done again with liquid yeast and a higher gravity beer in the 1.070 range the results would come out the same.

 

Yeah, you're right. I almost certainly am biased. But you can't argue with the higher viability at the end of fermentation. That's a pretty good indicator that the yeasties were happier. There's probably no/minimal difference in flavour but I just like knowing my yeast is happy and healthy.

 

Probably true. It was one of those things where I'm willing to try something to improve my beer.

Sweet jesus man! That's impressive.

I think your username is very fitting

 

I would argue that shaking is no more consistent than using O2 with a decent flow meter and timer. In both cases there are lots of variables that will affect the solubility of O2 - OG, temperature, etc. You won't always get ~8 ppm by shaking, that's just the average for a certain OG and certain temp.

Don't get me wrong, I'm not saying everyone needs to go out and buy an O2 system. You surely can make great beer without one. I'm just saying that there are some advantages to using O2, like if your only other option is to shake the carboy but you're not capable of doing that (injured, lazy, whatever). But the big one for me is being able to get more DO than possible using air, like if you brew beers that are better with 12 - 15 ppm DO. It's about the little things that all add up to make a better beer. Some people don't worry about controlling their fermentation temps. They might make some good beer, but that doesn't mean it's an OK solution for every situation.

 

Are you sure about that last part? First I've heard that and I don't recall reading that in "Yeast".

My understanding was that the maximum from using air is due to the amount of O2 in the air, not due to the OG.

 

It might not be in the book, but that doesn't mean it's not true. The temperature and gravity of the wort definitely affect the possible DO levels link - just like with CO2 when you carbonate your finished beer. The solubility of O2 reduces with increasing temp and gravity.

But yes, the concentration of O2 in the air plays a role, too. It's actually about the partial pressures of O2 in the two media.

 

Thanks for the link. (PS: I wasn't saying just because it wasn't in the Yeast book that it wasn't true. For all I know it was in there and I just don't remember).

Too bad they didn't do a study with different OGs and shaking. I'd love to see what the number is with a 1.100 wort. Is it 7.5 ppm or 4 ppm? That's a big difference. Do you have a link with that info?

 

Sorry, I don't know of any links with that level of info. I might do a Google Scholar search later if I have time.

Also, sorry if I sounded a bit narky. I didn't think you were saying that if it wasn't in Yeast then it wasn't true, but I know some readers will think that, so I wrote it bluntly (like some people still think How To Brew is the bible and everything in it is gospel - great book, but every book has its limitations).

 

I use O2 because I'm lazy and don't want to shake the fermenter.

 

Easy way to oxygenate is to rack the wort through a large funnel fitted with a screen.

 

Exactly my thing. I got tired of picking up and swirling full 6 gal glass carboys for minutes on end. Now I hit it with a wand for 1-2 minutes depending on og and also pitch healthy appropriate starters and my beers kick off in 8-12hrs and are done in about 2-4 days depending on how big the beer is. Works for me so I have no regrets buying an O2 wand system. But hey to each their own I'm sure the beer would be fine if I didn't aerate with pure O2 but I like the results for me anyway.

 

Wort spray aerator! They're only about $4 and work great.

 

I thought this was some insightful commentary from Dr. Clayton Cone about oxygen:

 

What flow meter do you use?

 

I believe it is a cardinal medical flow meter. I got it from eBay.

 

If I understand your post correctly the Brulosopher experiment isn't going to tell you anything about 02 due to using dry yeast. Looks like they need to do another test

 

I think it would be a great idea to perform the test with a jar of yeast (no starter) and a starter. It would probably be a good idea to do no shaking, shaking, and O2 as well.

 

Thanks. I did a quick search on "Cardinal medical flow meters", though, and there are way too many options! Do you have a model number or a picture? Any help would be appreciated! Thanks.

 

True Marshall but why spend $4 when you can spend $50 right? This is 'Merica'.... more is better lol. :cross:

 

They are coooooming! Make sure to follow the Blogs & Bloggers section, I can't post in these threads anymore.

Duh. How easy I forget.

 

Not entirely on topic, but not entirely off topic, one of the reasons I switched to O2 is for another tool in my belt to improve head retention. Head is generally made up of one-use-only proteins. The agitation/shake method uses a lot of those proteins up. I like to keep as much foam saved for my glass, rather than in the fermentor. Of course, many beers agitated for aeration come out with good head retention, but overall my head formation and retention are consistently better after switching to O2.