After the last couple xBmts on wort oxygenation, we received suggestions to focus these types of tests on beers that apparently require higher concentrations of O2, particularly high OG styles known for stalling early. We listened, tested, and the results are in!
Another great article, Marshall! Out of curiosity, how much time elapsed between the start of fermentation and packaging? To me, it sounds like the differences you’re picking up in your own tastings are what you’d expect from a young beer vs one with a little more age on it. Maybe the primary difference is simply that the no-O2 fermentation runs a little slower and just needs more time to “catch up” with the O2 batch (especially on a beer that is this big).
Greg brewed these beers, but I’m pretty certain he let them go about 3 weeks before packaging.
I suspect if the batches had been underpitched the results would have been more dramatic.
I gave away my O2 system years ago after reaching pretty much the same conclusion.
Yup. The aeration stone/wand + O2 tank is, in hindsight, one purchase I wish I wouldn’t have spent the money on. The setup mostly collects dust in the closet now due to how much of a PITA it is to keep in pristine working order plus I never saw any noticeable change in taste of beer, health of fermentation or time to fermentation completion for normal gravity beers compared to starting with “ready to rock” yeast and a healthy shaking/splashing of the wort before inoculation. If I were making a huge beer, I guess my normal MO would be to wait an extra few weeks in the primary anyway so NBD.
I honestly can’t tell a difference using a mix stir over when I used to use O2, even on big beers - or I’d have switched back. Aerating thoroughly and using plenty of healthy yeast get’s what I’m after.
THIS^^^^^
It kind of sounds like there was a perceivable difference in the malt aroma - less muddled in the pure o2 batch. Also, there’s the final gravity difference; the pure o2 batch clearly had an advantage.
I think the better argument is for shaking or using a mix stir versus pure o2 and there is where I see your point.
And I wouldn’t have just “given away” my o2 system. Sell that sh*t, holmes!
The aroma was perceivable by the biased brewer.
While the gravity difference is measurable - this is the second triangle that didn’t show a statistical +/- over the drier beer. This boggles me.
Let’s be careful about jumping to conclusions.
I am now really curious about this in a more delicate lager beer. Everything I read points to both vitality and biomass/weight needed for consistently well attenuated lagers - and O2 is discussed in depth in Boulton and Quain, as well as White’s Yeast book.
It was given to me, so I saw no reason to sell it. And yeah, I didn’t mean to imply that not adding O2 at all was a good idea. Only that I saw no difference between between O2 and a MixStir. And these days, using my pump to xfer to the fermenter aerates the wort as much as either O2 or a MixStir. Unless it’s a really high gravity beer, pumping and using that to aerate is all I do.
Blah blah, small sample size, yadda yadda, rigorous definition of significance, see my other comments. 
Seriously, though, be careful about reading too much into the results of a single trial when one taster could flip the test for significance.
Obviously! And lest there be any mistake, my results are true only for me. They are not intended to be an endorsement of any procedure for anyone else, only a report of what I learned and did.
From the experiment: “Two days prior to brewing, I spun up a couple 1.5 liter starters using previously canned wort then split a single vial of WLP007 Dry English Ale yeast between them, they were propagated on stir plates for 24 hours before being placed in my fridge to cold crash.”
So both starters were well oxygenated, allowing yeast to manufacture all the fatty acids and ergosterol needed to build numbers up. The main difference was that the yeast pitched into the aerated wort could make even more. Maybe if a starter is well aerated, there’s no need to also aerate the wort.
It’s all fine and dandy until you bring lagers into the equation.
I’m with you, I’ve never actually used O2 but my beers are at least as good those from dudes I know who do use it.
Cheers!
I agree with Sean. That said, combining these and similar results with my anecdotal evidence, I’m pretty convinced pure O2 isn’t a necessity on the homebrew scale… even for big beers.
I’d never give this advice though, as I’ve no desire to be tarred and feathered.
I’m not sure it’ll matter, but you better believe we’ll test it out.
I agree, Marshall. I think if you have an adequate, healthy pitch of yeast, then it doesn’t matter if you’re brewing a lager or an ale.
I’m staring to think vitality starters may be the log lost brewing secret, whether lager or ale, low or high OG. Got a lot more testing to do, but so far, I’m beyond impressed.
However, a stir plate without supplemental aeration does not provide as much aeration as home brewers have been led to believe. Plus, the turbulence encountered in stirred cultures results in the cells being stressed; therefore, the stir plate is not the true reason for the outcome.
The more accurate reason behind for the results in this test lie in the chosen strain’s O2 demands. WLP007 is Whitbread B. Whitbread B is a class O2 yeast culture with respect to O2 demands, which means that it is a relative lightweight when it comes to placing dissolved O2 demands on a medium. A class O2 yeast strain’s dissolved O2 demands can be met by dissolved O2 in the greater than 4ppm and less than or equal to 8ppm range. If this experiment were to be run with WLP037 in a closed fermentation vessel, the results would be more definitive.
For those who are wondering about O2 demand classes, Brian Kirsop wrote the seminal paper on the topic: http://onlinelibrary.wiley.com/doi/10.1002/j.2050-0416.1974.tb03614.x/epdf
By the way, in addition to being known as Wyeast 1098, White Labs WLP007, and Fermentis S-04, Whitbread B is also known as NCYC 1026.
NCYC 1026
Information
Flocculent.
NewFlo type flocculation.
1:5:4:5:5
O2, DMS 33 µg/l, low acetic, high lactic (which is why the strain produces slightly tart beers),
diacetyl 0.42ppm only, used commercially in Tower Fermenters (continuous process),
non head-forming, no estery flavour. Contains 2µ plasmid.
Depositor
British Brewery
Deposit Name
Saccharomyces cerevisiae
Month of deposit
June
Deposit Year
1958
Habitat
Ale production strain.
Interesting paper. Regarding the stir plate - even if the yeast cells from a stir plate are dead, they’ll still contribute ergosterol when pitched and will help make up for an O2 deficit.