That’s actually the least surprising part, IME. QA panels can never pick out small differences in FG.
And that makes perfect sense if you think about the role of oxygen. It’s to facilitate cell growth. If you pitch enough healthy yeast, then you need minimal, f any, cell growth.
waiting for Mark to tell me where I’m wrong…
I’m waiting Mark to confirm that 007 is not the same as S-04… I used to think so, then I was told it’s not… now I’m not sure.
I think the idea is if you pitch yeast with sufficient UFA and ergosterol reserves, they already have what they need for healthy replication and do not need to synthesize further sterols or UFA, which would require access to oxygen.
The healthy pitched yeast is still replicating, it just doesn’t need much dissolved O2 to do so.
Some people think that you don’t need to add any oxygen at all if using dry yeast.
I’ve heard one could oxygenate with olive oil.
Yes but then you have to enter is as Specialty Vegetable beer. Lambic if you also add parmesan
Yeah, I always thought S-04 was WY1099. Don’t remember where I learned that but maybe it was wrong.
The practice of a spinning a culture until it sediments results in low ergosterol and UFA reserves, which is why sedimented cells take longer to exit the lag phase and place higher O2 demands on the wort. The yeast from a White Labs vial will consume enough of the available carbon in a 1L starter that carbon will start to become limiting within 18 hours, resulting in the normal transition to quiescence. By twenty-four hours, only the cells from low viability White Labs cultures have not started to undergo the survival-related morphological changes that occur when carbon becomes limiting.
A stir plate does not aerate a culture. About all it does is keep the medium homogeneous and degas the culture. O2 pickup is bounded by the amount of surface area between the gas and the liquid based on Henry’s Law, which is why proper culturing glassware is short and wide (e.g., a Fernbach flask versus an Erlenmeyer Flask). Little to no O2 enters the fermentation after the culture starts to outgas because the culture is under positive pressure. Brewing strains do not reproduce aerobically in wort above approximately 1.008 due to being Crabtree positive.
Ergosterol production requires O2, and the ergosterol the is synthesized while O2 is still in solution is shared between mother cells and daughter cells. Ergosterol is used throughout fermentation to maintain cell membranes. Ergosterol is to yeast cells what cholesterol is to human cells. It is a precursor to vitamin D2.
That is correct. Dry yeast does not require O2 on the initial pitch due to the fact that it is propagated in a bioreactor below the Crabtree threshold, which results in aerobic growth versus anaerobic growth. Since ergosterol and UFAs are synthesized in the aerobic metabolic pathway and O2 never becomes limiting, the yeast cells have fully charged ergosterol and UFA reserves.
With that said, O2 is not the key to forcing aerobic growth. O2 and holding the amount of available glucose in a steady state below the Crabtree threshold is the key to forcing aerobic growth with brewing yeast because Saccharomyces is Crabtree positive. Aerobic propagation is significantly more efficient than anaerobic propagation. A yeast cell derives 18 times more energy by metabolizing glucose via the aerobic metabolic pathway than it does via the anaerobic metabolic pathway (36 ATP versus 2 ATP), which is why the big boys use aerobic propagation. Aerobic propagation requires a yeast propagator to be able to maintain a chemically static environment on a large scale. If you look up Fermentis’ parent company Lesaffre, you will discover that they are leaders in the design of bioreactors. Bioreactor design is a specialty within the field of biochemical engineering.
No, it is definitely Whitbread B. Wyeast 1098 is Whitbread B. Whitbread B is the most popular ale yeast strain in the world due to the fact that it is effectively a bottom fermenting ale yeast (i.e., why bottom fermenting and top fermenting are not good descriptions for lager and ale yeast strains).
As an aside, I do not know where Wyeast 1099 was originally obtained, but there are a lot of Whitbread strains. Whitbread maintained its own culture collection. NCYC 234, NCYC 235, NCYC 236, NCYC 238, NCYC 239, NCYC 240, NCYC 241, NCYC 242, NCYC 352, NCYC 353, and NCYC 1026 are all strains from the Whitbread collection.
Somewhere in his blog Ron Pattinson said that they had an unusual amount of strains they used for different beers.
1099 is crap. I’m never using that one again.
I’ve seen that S-04 is equal to 1098 and WLP007. See here:
I believe the false information about S-04 being 1099 comes from here, which does NOT seem to be 100% accurate:
Huh… that’s interesting. Is that why the krausen on a beer fermented with WLP007 looks so much different than most ale strains I’ve brewed with, i.e., not the thick, creamy type but instead a really airy, bubbly almost translucent krausen?
You don’t wanna go there…
Then why does an open stirred starter produce more biomass than an airlocked stirred starter?
Have you got a source to back that up? Low relative to what?
This is wrong. CO2 might not enter the solution when it’s outgassing CO2, but the amount of oxygen the solution can hold depend on the partial pressure of oxygen and the quantity of oxygen already present - not the quantity of carbon dioxide. They two gases don’t displace each other, they form their own equilibrium independently.
So, S-04 = WLP007? I did a split batch side by side a few years ago, the beers were different… though this was before my mind was totally fucked by the xBmt stuff.
And I will bet your statistical triangle test couldn’t tell the difference though…
I hate to say you’re likely right. Gonna have to do that one soon.