anticipating having to restart a stuck WY3724 saison

[couchsending]

I’ve used 3724 by itself once

I used yeast nutrient
Pitched a healthy amount of yeast at high krausen
Fermented it at 80-85+ controlled
Didn’t use an airlock

It stalled...

 

[Vale71]

Didn’t use an airlock

It stalled...

No way! Panic in the streets. The world is coming to and end!

 

[Qhrumphf]

Shame I don't have the gear, sounds like an experiment.

Identical three way split. For science. Only variable change-

1. Normal closed ferment (control)
2. Open ferment
3. Normal closed ferment with additional pure O2 added at 24 hrs.

My hypothesis is if #2 outperforms #1, #3 will outperform them both.

 

[suregork]

This is a bit off-topic, but this here is a prime example of how our findings in this recent preprint ( https://www.biorxiv.org/content/10.1101/654681v1 ) can explain some of the scenarios homebrewers encounter with saison strains (I started a separate thread a couple of weeks ago with the main results: https://www.homebrewtalk.com/forum/threads/solving-the-mysteries-of-diastatic-brewing-yeast.666744/ ). The main finding in our study was that many saison strains (i.e. those with the STA1 gene) have a deletion in the promoter of the STA1 gene. In simple words, many strains with the STA1 gene have a mutation that decreases the amount of enzyme produced.

We haven't tested WY3724, but based on everyone's experiences with it (i.e. it easily gets stuck, doesn't superattenuate easily) we can assume that this is a strain with a deletion in the STA1 promoter. We did test WLP565, and that strain had a deletion in the STA1 promoter. Another finding in the study, was that the saison strains (i.e. those that belong to the Beer2 clade) use the STA1 glucoamylase as the main mechanism for maltotriose use, and having the deletion in the promoter significantly decreases production of this glucoamylase and hence maltotriose use.

In practice, this means that when people use this strain and fermentation seems stuck, you most likely are in a situation where the yeast has consumed all the maltose and glucose from the wort and most of the maltotriose remains (this is usually around 1.018-1.024 in a 1.060 wort). The STA1 enzyme is still produced at very low levels in strains with the deletion, so with time the yeast might consume most of the maltotriose. The main factor that encourages production of the STA1 enzyme in strains with the deletion is oxygen. So this could be one of the reasons that people have reported better attenuation with open fermentations. Adding another yeast late is fermentation might not work, since the wort contains almost exclusively the complex malt sugars at that point (but can always be tried).

 

[Gregory T]

Actually I've used 100% DuPont (3724 edition) a good few times, with an airlock or a blowoff, and no stall. Every single time I've used pure Dupont it has never stalled, and every time it's had an airlock. I just crank pure Dupont hotter than I do blends.

I said all that already. You read what you wanted.

I don't deny that pressure is a difference.

The impact of pressure on yeast activity is well known. It's why open ferments are typically done in short, squat, often square fermenters. As opposed to mostly vertical conicals.

But scale becomes an issue. Because a yeast cell doesn't change size between a 5 gallon batch and a 120bbl batch. But the hydrostatic pressure certainly does, along with, relatively, much narrower blowoff piping for the batch size and amount of CO2 created.

What the other poster is pointing out, validly, is that the the pressure difference between airlock and no airlock is minimal at best and easily overshadowed by other factors.

That doesn't mean there's not something else going on. It means it may not be pressure at this scale.

You're creating a correlation you have nothing but anecdote to support. It doesn't mean you're wrong about the result. Anecdote is still evidence, albeit weak evidence. It means more research is needed. But scientific knowns about pressure are stronger, and suggest that, at homebrew scale, pressure is NOT the factor. Another poster suggested oxygen access, which makes far more sense.

But, you CAN use pure Dupont with an airlock and not stall.

I’m not saying it’s pressure. I don’t know why it doesn’t stall in an open primary. I frankly don’t care. I know that it works

It could be psi. It could be dissolved CO2. It could be that when it’s open some wild 3711 finds its way in. It could be something else entirely

What I do know is that when I brew a Saison with DuPont yeast and leave it open for 8 days. It reaches final gravity

That isn’t speculative

The only other person I’ve read that didn’t get a stall was removing their lid and checking gravity daily, hence removing pressure/allowing CO2 out/allowing wild 3711 in/ or whatever reason that it works

But hey if the DuPont stall is a myth then you should recommend the OP does not need to do anything. Take gravity measurements weekly and let us know how it goes.

Of course you said you raised temperature didn’t you? Well have to not to that

I mean it could be an either or thing. Use an airlock and raise temperature or leave temperature and don’t use an airlock

I mean not that long ago no one knew yeast existed. They still made beer

 

[Gregory T]

Now that I think about it and I’m no chemist. Maybe it’s dissoved CO2. Leaving the airlock with off would lower that and so would increasing the temperature

 

[Miraculix]

This is a bit off-topic, but this here is a prime example of how our findings in this recent preprint ( https://www.biorxiv.org/content/10.1101/654681v1 ) can explain some of the scenarios homebrewers encounter with saison strains (I started a separate thread a couple of weeks ago with the main results: https://www.homebrewtalk.com/forum/threads/solving-the-mysteries-of-diastatic-brewing-yeast.666744/ ). The main finding in our study was that many saison strains (i.e. those with the STA1 gene) have a deletion in the promoter of the STA1 gene. In simple words, many strains with the STA1 gene have a mutation that decreases the amount of enzyme produced.

We haven't tested WY3724, but based on everyone's experiences with it (i.e. it easily gets stuck, doesn't superattenuate easily) we can assume that this is a strain with a deletion in the STA1 promoter. We did test WLP565, and that strain had a deletion in the STA1 promoter. Another finding in the study, was that the saison strains (i.e. those that belong to the Beer2 clade) use the STA1 glucoamylase as the main mechanism for maltotriose use, and having the deletion in the promoter significantly decreases production of this glucoamylase and hence maltotriose use.

In practice, this means that when people use this strain and fermentation seems stuck, you most likely are in a situation where the yeast has consumed all the maltose and glucose from the wort and most of the maltotriose remains (this is usually around 1.018-1.024 in a 1.060 wort). The STA1 enzyme is still produced at very low levels in strains with the deletion, so with time the yeast might consume most of the maltotriose. The main factor that encourages production of the STA1 enzyme in strains with the deletion is oxygen. So this could be one of the reasons that people have reported better attenuation with open fermentations. Adding another yeast late is fermentation might not work, since the wort contains almost exclusively the complex malt sugars at that point (but can always be tried).

Thanks very much for the insight, that pretty much confirms my hypothesis above

 

[Qhrumphf]

I mean it could be an either or thing. Use an airlock and raise temperature or leave temperature and don’t use an airlock

That does seem to be the options, yes. Trying it cooler and open has been on the list for years but haven't gotten around to it.

And in fairness, your first post in this thread attributed it to backpressure as per the link you posted.

 

[Vale71]

Leaving the airlock with off would lower that and so would increasing the temperature

No it won't, at least not until primary fermentation is finished. The reason being the rate at which CO2 is produced by yest far exceeds the rate at which CO2 can escape. Once fermentation is finished then of course the CO2 content will diminish as CO2 diffuses out of the beer and is no longer replaced by newly produced CO2. Which is one of the reasons why in commercial operations that still practice "open fermentation" beer is transferred to maturation vessels before FG is reached (for spunding purposes).
To claim that this is the cause for fermentation not stalling is absurd as the reduction would only happen once fermentation stops, so that the cause would follow its own effect which is patently absurd. In a sicientific context of course, in a magical interpretation all bets are off...

Edited to add: in all fairness there will be a negligible difference not attributable to CO2 escaping without an airlock versus CO2 not escaping with an airlock as the latter is obviouly false. CO2 escapes with an airlock too, as proven by the airlock itself bubbling happily. The only difference is again attributable only to the slightly elevated headspace pressure, so we are back again to the 1-2 mbar increase in pressure which will induce an increase in CO2 content of a few ppm at best and that's totally negligible over a normal content of 2-3 parts per thousand, dependent on fermentation temperature.

 

[Qhrumphf]

No it won't, at least not until primary fermentation is finished. The reason being the rate at which CO2 is produced by yest far exceeds the rate at which CO2 can escape. Once fermentation is finished then of course the CO2 content will diminish as CO2 diffuses out of the beer and is no longer replaced by newly produced CO2. Which is one of the reasons why in commercial operations that still practice "open fermentation" beer is transferred to maturation vessels before FG is reached (for spunding purposes).
To claim that this is the cause for fermentation not stalling is absurd as the reduction would only happen once fermentation stops, so that the cause would follow its own effect which is patently absurd. In a sicientific context of course, in a magical interpretation all bets are off...

Edited to add: in all fairness there will be a negligible difference not attributable to CO2 escaping without an airlock versus CO2 not escaping with an airlock as the latter is obviouly false. CO2 escapes with an airlock too, as proven by the airlock itself bubbling happily. The only difference is again attributable only to the slightly elevated headspace pressure, so we are back again to the 1-2 mbar increase in pressure which will induce an increase in CO2 content of a few ppm at best and that's totally negligible over a normal content of 2-3 parts per thousands, dependent on fermentation temperature.

And we're back to....oxygen access.

Which suregork very much seemed to validate.

I wish I had access to my old pilot system where I could set it up for a closed O2 injection. Because I'm legit curious about a second oxygenation regimen and what impact it'd have.

I can't close it enough when adding O2 at home to make it valid enough for my standards.

 

[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.