anticipating having to restart a stuck WY3724 saison

[Vale71]

Again, you won't have actual O2 in the beer until fermentation is over and the Kräusen falls. The Kräusen acts as a barrier and constantly pushes O2 away from the surface of the beer preventing its diffusion. It's a good thing too otherwise you'd have premature staling in anything but a hermetically sealed fermenter.
Once the Kräusen falls it's all bets are off unless you transfer timely to a maturation vessel. Any causative relationship with a stalled fermentation is again implausible as the cause would have to follow its effects. QED.

 

[Qhrumphf]

A closed container with an airlock under positive pressure is one thing. Once they yeast has taken up the available O2 that's it.

But in an open environment? Yeah there's outflow of CO2, but yeast will take up O2 too, especially during their growth phase. And you're gonna get O2 into the space above the fermentation.

Otherwise air exchange during propagation would be a pointless endeavor. Only that initally dissolved would matter.

And I thought the krausen/pellicle oxygen barrier had mostly been debunked.

Not my field of expertise, but this rings contrary to what I recall from fermentation biochemistry. Maybe I'm wrong though.

 

[Miraculix]

How is the diastaticus enzyme working? Is the yeast getting the logner chains into the cell and then the enzymes chop it up inside of the cell or are those enzymes released into the surrounding medium and run havoc on whatever sugar they get in contact with? If the enzymes would be released, a limited amount would be necessary to enable full conversion of the longer sugars into something easy to metabolise for the yeasts. Meaning that a small amount of oxygen would be enough.

Krausen is not a solid medium like glass, it let's gasses pass over time. It is also not a thing that actively pushes anything away.

 

[Qhrumphf]

How is the diastaticus enzyme working? Is the yeast getting the logner chains into the cell and then the enzymes chop it up inside of the cell or are those enzymes released into the surrounding medium and run havoc on whatever sugar they get in contact with? If the enzymes would be released, a limited amount would be necessary to enable full conversion of the longer sugars into something easy to metabolise for the yeasts. Meaning that a small amount of oxygen would be enough.

Krausen is not a solid medium like glass, it let's gasses pass over time. It is also not a thing that actively pushes anything away.

I recall reading that the enzyme can survive heat treatment that would kill the cell itself. Leads me to believe it's secreted and external to the cell. Same piece (on MTF wiki) probably clarified but I don't recall either way.

 

[Vale71]

It's an exo-enzyme. It's secreted outside the cell walls and then the simpler sugars are absorbed through the usual transport mechanisms. That's one reason why this process is so slow and also very taxing for the cell. Enzymes have to be produced in a continuous fashion and then cast into the environment in the hope of reaping some reward. Contrast that with enzymes in the cytoplasm that maintain their function for a long time and only need to be replaced when they are eventually degraded through aging.

 

[Miraculix]

It's an exo-enzyme. It's secreted outside the cell walls and then the simpler sugars are absorbed through the usual transport mechanisms. That's one reason why this process is so slow and also very taxing for the cell. Enzymes have to be produced in a continuous fashion and then cast into the environment in the hope of reaping some reward. Contrast that with enzymes in the cytoplasm that maintain their function for a long time and only need to be replaced when they are eventually degraded through aging.

Ok, then my theory is as follows. As long as there are still simple sugars present, there's obviously no need for the enzymes so the cell doesn't produce them.

As soon as the simple sugars are gone, the yeast starts excreting the enzymes, at least when there is a little bit of oxygen present to kick-start the denatured sta gene.

I have obviously no idea how this kickstart happens and why is necessary but I guess that there is an enzyme precursor or production of the enzyme itself that needs a bit of oxygen, at least with the damaged sta gene present.

Only a bit oxygen is enough because once there, the enzymes work and continue working until being denatured, which takes time at given temperatures. Meaning there's no need for a continuous production of enzymes, one portion of it should suffice.

And why doesn't it always work with every "open" fermentation? I think there is a huge difference between a thin bottle neck with an airlock without water and a bucket without a lid. Maybe the first mentioned doesn't provide enough air exchange to provide sufficient amounts of oxygen.

 

[Tom R]

Well, it turns out that my LHBS had only 3711, so that's what I pitched. Still want to try again with 3724.

I can say that my 1.048 OG went final at 1.001 in 4 days.

Much of this discussion was over my head, but it's still interesting to read, thanks!

 

[brownni5]

That’s an interesting opinion

The facts are, I brewed 3 saisons back to back to back without an airlock which hit FG’s of 1.002, 1.001 and 1.002 in 8 days with nothing but aluminum foil over the airlock

whether it’s pressure that stalls it or something else, if you want to avoid the DuPont stall I recommend no airlock

FWIW - I've never had 3724 stall, and I always use an airlock. I think Brulosophy found the same thing.

 

[dbayub]

FWIW, I was just at Dupont and took the tour. They are very particular about how they do things, from the gas-fired copper kettles to the horizontal fermenters (with airlocks, btw). They even have a special add-on to their bottling line to place the bottles horizontally in a case for conditioning, because they say it makes the beer taste different. If I'm remembering correctly, they start fermentation @ 23c (73f) and ramp up to 30c (86f) (may have been even higher).

Other Belgian brewers, when asked about Dupont's bottle conditioning, rolled their eyes.