No-Chill vacuums and Pressurized Fermentation Aeration and Pitching Questions

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WortMonger

"Whatcha doin' in my waters?"
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I have been thinking about several things lately after reading posts on the forum. I, like most of you, read something that may not even be remotely what I am thinking about and then BAM... idea! Since we have such a wonderful vehicle of running ideas back and forth here on HBT, I thought I would post my latest ponderings. I hope to get some absolute answers with evidence, so I can nip stuff that is just silly in the bud, but I invite all of you to chime in with criticisms. Everything helps when you are trying to work through an idea. First let me start with saying that, in the past people thought things like no-chill, pressurized fermentation, and other such "outlandish" ideas were stupid. Some people still think they are, so those would be the only comments I would prefer not to clutter up the thread... if you please.

Most of you guys know I am a pressure fermentor. I love the ease it gives me, and I love the end product as well. Having never said it is any better than normal ways, I will defend to the death that it is in no way any worse than normal fermentation techniques. This, of course, with exceptions of certain beer styles that require what pressure fermentation won't allow (ie. estery beers). Reading and hearing about no-chill, it got me to thinking that P-Ferment kind of lends itself to the no-chill procedure in the facts that you need a container that can stand the heat from the boiling wort and the vacuum created after the cooling occurs in a sealed container. A keg would work appropriately in both situations, as well as for a pressurized fermentation once the yeast is pitched.

I have seen before, but cannot find now (please link me if you find it), breweries using steam cleaned kegs in which a vacuum was created from cleaning and cooling. They filled the kegs with beer, equalizing this vacuum and ending up with pressurized beer storage. Once you have a keg filled with wort and a vacuum, the problems I foresee making this "easy" are aeration and inoculation. I have no idea what kind of vacuum we are talking about here, with 15 gallons of boiling wort sealed up in a Sanke keg and allowed to cool, but I assume it would be significant. Canning creates these same pressures though, and glass seems to hold up nicely. Now, on to my way of thinking so you guys have something specific to chime in on. With before said keg o'wort under vacuum and at temperature to pitch, how would you go about aerating it? How would you go about pitching it? Remember, the whole point to it being sealed is to remain in as sterile an environment as it can possibly be.

My thoughts and wonders:
Aeration - Could I simply hook up my O2 tank and fill the Sanke, equalizing the pressure? Would I have to stop after 2-3 minutes like when I use my stone and wand? Since I wouldn't be using a stone, would I have to stop even sooner (since obviously more O2 would be allowed to go in being under less resistance with no stone)? Would it be pointless to oxygenate through the dip tube, meaning no matter how I got the O2 in there it would be fine? I'm thinking shaking needs to be done no matter what anyway. Is there something I am not thinking about while under a vacuum about O2, like does it act differently or would it be able to be absorbed into the wort? You see where I am going by asking, so hopefully you can help with this line of questioning. If O2 absorption is impossible under a vacuum, would pitching first and then equalizing with HEPA air filters/other equalizing procedures be the way to go prior to aeration? As long as the beer receives the O2 it needs for a good start, I couldn't care less if it were still under a vacuum (of course if this is possible). Once fermentation starts, it will produce CO2 and have excess pressure relieved out of the spunding valve just like any other pressure ferment.

Pitching - I'm really thinking about doing starters in 2 liter pop bottles, or at least combining the yeast in some size pop bottle after decanting. I would like to make a connector to combine a bottle fitting to a tap connector, so that when the tap is engaged it could suck the contents of the bottle into the keg. Of course, you would have to rig the connector by removing beer-out check valves and capping the gas port. The liquid and yeast would be sucked in before the bottle collapses into the tap port hole. I really don't think it is possible for the bottle to enter the tap connector in any way... again, maybe I am wrong but it just seems impossible. Once you have dosed your beer, un-tap the connector and the bottle would release its vacuum allowing it to be taken off. Again, after this as your first procedure you could then aerate to recommended O2 volumes (if the vacuum allows you to do this), or equalize the pressure with O2 and shake to aerate.

I think this is long enough as a start. I will explain further my thoughts if the tangents are brought up, but these are the basic things I am wondering about for using my equipment in this way. I am sorry about all the questions, but if you don't ask... you don't get answers.:mug:
 
I find your idea...interesting.

What are you thinking the process is going to be? Are you going to boil in a container, then transfer the boiling hot-wort into a sealed vessel? Or are you going to boil in a vessel, then seal it?

In the brewery, they are filling a huge vessel with steam, and when that steam cools down, it is going to condense into a vary small amount of water, which is what generates the significant vacuum. If you fill a vessel with hot beer, seal it, and then it cools down, the beer won't contract nearly as much as vessel filled with steam does...more significant, I think, is going to be the amount of airspace remaining in the vessel, as any air left in the vessel will heat up from the hot wort and (assuming the vessel is vented to let you get the wort IN and thus has the same pressure as the environment when you close it) it will contract when it cools down...but I wouldn't think the vacuum would be huge.

The problem is that a keg is designed to resist internal pressure, not external, so I don't know how to tell how much external pressure it can withstand, short of hooking a vacuum pump up to one and seeing when it breaks. Of course, that's going to destroy the keg...

Also, I see a problem with your 2 liter bottle idea. If you have enough vacuum to draw 2 liters of liquid in, that might be enough to destroy the bottle. The collapsing bottle isn't going to just let all the liquid inside flow easily into the keg, it is going to collapse like a crushed can, probably rupturing and letting in air...which is obviously bad.
 
Yeah, I figure boil in the kettle and transfer to the Sanke while allowing gas to escape. Once full, un-tap and then you are sealed.

I didn't realize that the steam would be much greater vacuum pressure than cooling wort... very interesting and good information in my case.

I hear you about a keg being designed to hold pressure not a vacuum. Quite the same way in which a mason jar is meant to hold a vacuum and not pressure, but... we all know you can do the opposite with both to an extent. I feel 100% confident that a Sanke can withstand the vacuum pressures exerted during the cooling period just by design alone. The only place I see where it would be vulnerable is the ball on the stem, and if it were to let in a bit of air there... so be it. I would just make adjustments to keep any incoming air there as filtered as possible. Now, a Corny keg is a different matter altogether. The way it seals would not hold up to a vacuum. Heck, they won't even seal most of the time without setting them with pressure.

I am really hopeful not to do anything but squish the bottle during the vacuum transfer of contents... hopeful. I really don't see them rupturing inwards, maybe to much pressure... but then they usually just stretch at first. I am thinking it will be just like rolling/squeezing all the air out, and put the lid back on to gain that extra bit of room in the bag for more trash.

Hope that clears up my thoughts on your questions. Thanks for your fast response by the way. :)
 
Yeah, I figure boil in the kettle and transfer to the Sanke while allowing gas to escape. Once full, un-tap and then you are sealed.

I didn't realize that the steam would be much greater vacuum pressure than cooling wort... very interesting and good information in my case.

I hear you about a keg being designed to hold pressure not a vacuum. Quite the same way in which a mason jar is meant to hold a vacuum and not pressure, but... we all know you can do the opposite with both to an extent. I feel 100% confident that a Sanke can withstand the vacuum pressures exerted during the cooling period just by design alone. The only place I see where it would be vulnerable is the ball on the stem, and if it were to let in a bit of air there... so be it. I would just make adjustments to keep any incoming air there as filtered as possible. Now, a Corny keg is a different matter altogether. The way it seals would not hold up to a vacuum. Heck, they won't even seal most of the time without setting them with pressure.

I am really hopeful not to do anything but squish the bottle during the vacuum transfer of contents... hopeful. I really don't see them rupturing inwards, maybe to much pressure... but then they usually just stretch at first. I am thinking it will be just like rolling/squeezing all the air out, and put the lid back on to gain that extra bit of room in the bag for more trash.

Hope that clears up my thoughts on your questions. Thanks for your fast response by the way. :)

I'm feeling that the keg itself, from a construction standpoint, will be able to handle the vacuum. The various fittings, I don't know.

As far as soda bottle goes, the max you are going to be crushing it with would be ~ 15 psi (since that is absolute pressure at sea level.)

If you had a container you could toss an empty, closed bottle into, then pressurize with 15 psi, you'd have an idea what will happen do it. Mostly, though, I'm getting at the fact that it isn't going to suck your slurry out of the bottle very well, unless you have a way to let air into the bottle to replace the lost volume. Otherwise, the bottle is going to collapse until the pressure is equalized. And once the pressure is equalized, nothing more will come out of the bottle...
 
I guess I am not understanding, or perhaps I didn't lay it out properly. The bottle would be upside-down connected to the tap connector on the Sanke. The liquid would be below any gas in the bottle, so once tapped... it would be the first to enter the Sanke. The crushing would only squeeze more into the Sanke IMHO. I was even thinking of using this technique without a vacuum, only then I would have to vent pressure from the keg to allow the contents to enter the Sanke.
 
I guess I am not understanding, or perhaps i didn't lay it out properly. The bottle would be upside-down connected to the tap connector on the Sanke. The liquid would be below any gas in the bottle, so once tapped... it would be the first to enter the Sanke. The crushing would only squeeze more into the Sanke IMHO. I was even thinking of using this technique without a vacuum, only then I would have to vent pressure from the keg to allow the contents to enter the Sanke.

How much airspace are you going to have in the 2 liter? Basically whatever air space is in the container is going to be able to increase directly in proportion to the drop in pressure. So the pressure in your bottle is 15 psi, and the pressure in the keg is 5 psi (a 10 ps vacuum) the airspace in the container would triple in size IF the container were perfectly rigid. Now, how external pressure it takes to crush that 2 liter bottle...well, I can tell you it isn't going to be much.

If we can get an accurate idea of the headspace in your keg after you put in your wort, we can calculate roughly the pressure drop...
 
Very interesting indeed. Dorklord covered the first things to jump out at me, can the keg withstand the vacuum, can the 2-liter bottle withstand the vacuum, and will it really dose the yeast?

What about dosing the yeast using air pressure? I am not sure that you would want to do it with O2, as it may be that such a concentration of O2 directly on the yeast would not be good for them. I really don't know.

Shaking would be a pain. I suppose you could automate it or just roll the keg around.

Controversial, but have you considered skipping the O2 and the shaking and using olive oil? <ducks>
 
How much airspace are you going to have in the 2 liter? Basically whatever air space is in the container is going to be able to increase directly in proportion to the drop in pressure. So the pressure in your bottle is 15 psi, and the pressure in the keg is 5 psi (a 10 ps vacuum) the airspace in the container would triple in size IF the container were perfectly rigid. Now, how external pressure it takes to crush that 2 liter bottle...well, I can tell you it isn't going to be much.

If we can get an accurate idea of the headspace in your keg after you put in your wort, we can calculate roughly the pressure drop...
Since this is such an unknown, lets just say you did a almost full 2 liter starter. Then you decanted, as normally you would to have "?that amount?" of yeast and remaining liquid available for dosing (so not a lot of filled up space in the 2 liter). Attach the bottle to the tap connector, with a valve in-between of course or you would just dump your starter immediately. Tap the connector and open the valve. Wooosh, yeast should rush in and the bottle is crushed trying to equalize the pressures. Now, there is still a vacuum (amount to be determined) inside the keg, since the bottle was the only amount of air supply and pressure equalization available (gas port on tap connector being capped). I can suck a 2 liter pretty much to flat with just bellowing my cheeks, so I know it wouldn't take much vacuum pressure to accomplish this. I am thinking at this point, I would simply fill the remaining airspace in the keg vacuum with pure O2 and shake (whether that be through the beer port and hence through the wort, or through the gas port if it doesn't matter). Since it is a 15 gallon batch, we are only talking about .5+ gallons of space minus the amount in the yeast pitching bottle. I hope this is enough information for you to figure out a broad spectrum of what it might take to accomplish what I am wondering. I am very glad you have the knowledge of vacuums and pressures.:D

Very interesting indeed. Dorklord covered the first things to jump out at me, can the keg withstand the vacuum, can the 2-liter bottle withstand the vacuum, and will it really dose the yeast?

What about dosing the yeast using air pressure? I am not sure that you would want to do it with O2, as it may be that such a concentration of O2 directly on the yeast would not be good for them. I really don't know.

Shaking would be a pain. I suppose you could automate it or just roll the keg around.

Controversial, but have you considered skipping the O2 and the shaking and using olive oil? <ducks>
If I were to use any pressure, I would just put the yeast in a keg and do it with CO2 to the other keg. I am trying to think outside the box, and not have to pressurize anything. this is about using the already created vacuum to my advantage. Shaking a keg is hopefully not what I end up doing. I would like to find a great way to aerate with the currently described situation. Olive oil is possible, for the starter but not in my beer. That is bit more controversial than I am wanting to get. I'm thinking more technique not chemical reactions, but thanks for your response.:mug:
Actually, pressurizing the 2 liter might work, but how would you hook it up?
More problems than I want to deal with. Something I didn't mention earlier is, if I had the bottle to beer-nut connection on my tap connector for this yeast pitching idea... I could hook up a White Labs vial and it would fill with beer for taking samples and measurements during the primary fermentation. Another use for the contraption if the vial was able to fill (poses another question huh, like would there be a build up of gas in the vial and not allow a testable amount of beer to enter it). Keep it coming guys, I am enjoying it.
 
It looks like the temperature drop from boiling, to 70 F, should take pressure from 1 atmosphere to .8 atmospheres, which means about a 3 psi difference. Now, water vapor in the air will give a bigger pressure drop than that, and the wort will shrink to some extent as well, but still, we're looking at a few PSI vacuum.

Probably enough to suck the yeast out of your bottle, but that pressure is going to equalize pretty quickly (.4 gallons of fluid pulled into your keg will be enough to equalize the pressure)

Now, that's going to be if you have no pressure in the keg, and the heat of the wort is enough to heat up whatever air is in the keg to ~200 F, which seems reasonable to me (you are going to have leave your vent open long enough for the wort to heat the rest of the air in the keg, as if the air is still cold when you close it, you'll build pressure as the air is heated!)
 
Good question. I'm not sure. On the one hand, it isn't much volume of air to heat up. On the other hand, air isn't the most effecient method of transferring heat.

I think it would work to just bleed the pressure off for the first few minutes, until it stops building pressure.
 
Alright, thank you dorklord for what you have contributed, and you jeffmeh for your interest in this. What I have so far is what I was hoping for and thought would happen.

1.) The hot wort filled keg will surely hold up to the minimum vacuum that will be created during the filling and cooling process.

2.) This vacuum is not going to be enough to first, not suck the wort out of the 2 liter (or smaller sized) starter pop bottle, or secondly enough to implode the bottle to the point of sucking it inside the tap and keg. <--- I knew this in my head and heart, but I have been unpleasantly surprised before by seemingly non-ominous, but catastrophic, experiments that made me say :eek:.
I am glad the above has been resolved, but that just leaves a bit more to complete the thoughts I have. To recap and keep the answers coming in streamlined for ease of understanding to me, here's what I still need from you smart people. Feel free to just quote the question(s) and then post your answer(s). Might make it that much easier to read.

First question: How would you suggest I go about aerating it, based on the fact that I will not be moving the wort after it is in the keg and at pitching temperature?

I have been through the numerous research, read Yeast, and done many a batch of beer, and the one thing I can say is that I am after the cleanest profile possible with using the Closed-System Pressurized Fermentation Technique. That being said, I am after that with No-Chill Method as well. Lower esters, lower fusels, etc. are where it is at for my taste buds. Understanding this, I would use a different approach for beers where these flavor characteristics are wanted, but aeration crosses the gap where technique has the ability to divide it into different things. I want the yeast to have what it needs, and it needs oxygen. I could use olive oil in my starter, higher yeast pitching rate, or any other method for not worrying about aerating my wort... but I have only done properly aerated batches and am not comfortable trying these techniques without some good "been there, done that" personal accounts on you guys parts.

Second question: Is there a specific technique you guys might recommend in my case? Or, am I going to be OK pressurizing the keg (psi unknown so if you have a recommendation...) with pure O2 and shaking/rolling/agitating?
It's a 15 gallon keg, so not that easy a job though still doable. I hope to get this aeration issue resolved as convincingly as the pitching was answered.
Last question: If I had fermenting beer in a keg, pressurized to say 30 psi@ 70*F, could I do the following? Hook up a White Labs yeast container to the normally beer-out post on my tap connector on the fermenting keg (my spunding valve setup). The setup would be the same as when pitching, with a valve between the container and the connector. Once tapped, and the valve opened, would the vial/container fill with enough beer to test? I can't understand how the pressure of air in the vial would react. Help with this please?
 
It's beyond my readily available knowledge, but one could calculate the atmoshpheric pressure level required to bring the keg with O2 that would properly saturate the wort, given the temperature and head space, correct? I imagine you could come up with an oxygenating chart similar to a carbing chart for your desired O2 saturation. Taking the analogy further, there must be some "burst carbing" equivalent that would speed up the process. Of course, you probably already know this and are looking for someone with the knowledge and skills to do the math.

As far as agitating goes, the simplest and least desirable option would be to roll the keg. Another idea would be a scaled up shake table. They make some silly massage/exercise devices, but I do not know anything about them. Perhaps you rig up some DIY equivalent. Yet another idea would be to suspend the keg from the ceiling with some heavy duty bands so that it is virtually weightless, and put some slight downward force on it and let it "bounce." Heavy duty bands: http://store.sorinex.com/CrossFit_Bands_s/167.htm


Regarding your final question, if the valve on the keg is attached to the dip tube and submerged in liquid, I would think the vial would fill until it reached the pressure of the keg, while compressing the air in the vial. Does sampling really need to be closed, or could you just run a line into an open container?
 
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Well, I know you use regular Sanke's for your fermenters, but on mine I have a bottom dump. I also use an in line oxygenation stone that's in a tri-clamp tee which I take off of the boil kettle and take to the fermenter to do in line carbing during transfer (have yet to actually do it, cause I'm doing pressure ferments most of the time).

Put it on the bottom dump and inject away. I know this is how some folks do it with big fermenters which don't have stones already in them (jerry-rig unitank), they just do it thru the bottom dump. Think I read that on the probrewer forums.
 
It's beyond my readily available knowledge, but one could calculate the atmoshpheric pressure level required to bring the keg with O2 that would properly saturate the wort, given the temperature and head space, correct? I imagine you could come up with an oxygenating chart similar to a carbing chart for your desired O2 saturation. Taking the analogy further, there must be some "burst carbing" equivalent that would speed up the process. Of course, you probably already know this and are looking for someone with the knowledge and skills to do the math.

Regarding your final question, does sampling really need to be closed, or could you just run a line into an open container?
Yes, I need the math to see if this is worth while or if another way is needed to succeed.

Final question was answered. I already have a testing spigot and that way works just fine.

Well, I know you use regular Sanke's for your fermenters, but on mine I have a bottom dump. I also use an in line oxygenation stone that's in a tri-clamp tee which I take off of the boil kettle and take to the fermenter to do in line carbing during transfer (have yet to actually do it, cause I'm doing pressure ferments most of the time).

Put it on the bottom dump and inject away. I know this is how some folks do it with big fermenters which don't have stones already in them (jerry-rig unitank), they just do it thru the bottom dump. Think I read that on the probrewer forums.

Thanks SankePankey, but that would work much the same as going into the beer-out dip tube and bubbling to the surface inside the keg. I would have to let pressure build otherwise I would have a ton of foam coming out the gas port on my tap connector.

Keep it coming guys! I am just hoping to hear that one idea that I couldn't think of that would easily aerate inside a keg. I'm still thinking filling to a pressure of O2 and shaking every 15min or so.
 
I just no chill in one keg, make a good sized starter from left over wort, decant that into a new keg the next day and then rack the beer onto the starter, usually going through my gas-in to foam it up some. If I'm paranoid, I purge/lightly pressurize the second keg after adding the yeast with oxygen first, so that it splashes and mixes with pure oxygen, but I find that i don't need to in general. 8-10ppm with a good starter works pretty well for me. Under pressure, you get more dissolved everything, so that can help some.

But I think that you're trying to no-chill into one keg, and then never expose the contents of that keg to anything else if you don't have to, right? I'd say that you eiether need to push the oxygen in your dip tube and lightly pressurize like you siad, or use the 2-liter or whatever bottle setup to give yourself a large effective headspace that you oculd purge with O2. I tried to find the results of a guy that did just pressurize the headspace with oxygen and said it worked well, but I can't find them...

I'm still wondering that if you pressurize with oxygen if the pressure is going to essentially do the "shaking" for you...
 
Some quotes from a guy undergoing some oxygen tests:

"According to Fix (Principles of Brewing Science) O2 uptake is very rapid by the yeast, usually within a few hours. Palmer states less than an hour. I assume this depends on how active the yeast are when pitching, but if pitching from a fresh starter, it seems reasonable that they're going to be taking up a lot of this O2 pretty quickly.

Too much O2 will result to overly vigorous fermentation and excessive yeast growth, potentially resulting in off flavors, particularly esters (Lewis/Young, Brewing), (Fix, Analysis of Brewing Techniques)."

http://blog.flaminio.net/blogs/index.php/beer/oxygen/

He says that his most consistent results have been from oxygenating the headspace and stirring/shaking, and that you don't need a lot of oxygen, you just need a good way to get it into solution. Just make sure that it's done before, or immediately after you pitch.
 
This is the kind of information I have been waiting for. I figure, from dorklord's info, that I will probably not have much negative pressure after my pitching method. Since my spunding valve will be on the fermentor when I am oxygenating the wort through the beer-out port, I can see the psi reading instantly.

Now I just need more definitive information on how much psi I should be looking for, so that when I start shaking I can see how much is going into solution.

I shake my keg at the end of primary anyway, to rouse yeast for better clean-up and to make sure I am getting my carbonation level right at the temperature it is at. So, this would just be more of that. Being a completely closed system outweighs this minimal of a hassle to me.

So... Last remaining question is: At .5 gallons of head space, what psi of O2 is needed to be shaken and absorbed into solution to achieve the ppm desired for great fermentation?

I can't thank all of you guys enough for helping me think this think out. I am medicated from a bad upper respiratory infection and this stuff is easy to understand, so thanks again.:mug:
 
I had an order from amazon today that I was thinking would be perfect for your situation. http://bit.ly/ 500ml bottles that you can autoclave, unfortunately the price posted when I bought them must have been a typo because they are now up to $53 and I only paid $5.50.

My thought is to modify one of the tops with 2 dip tubes. One running all the way to the bottom and one short. On the long one put a hepa filter and the short one a tube running to your fermenter. Hook it up, invert the bottle, open any valves, then your vacuum and gravity should take care of the rest and any makeup air that goes in will be hepa filtered.

You could skip the inverting step and use co2 or o2 (maybe) to push it out like a mini keg.
 
It's a 15 gallon keg, so not that easy a job though still doable. I hope to get this aeration issue resolved as convincingly as the pitching was answered.

I'm reading the Yeast book currently and just ran across something relevant. "Filling the headspace of the fermentor and shaking vigorously can result in dissolved oxygen levels past 10 ppm, but once you have bottled oxygen, it is much easier to use a sintered stone"

So no idea what PSI to go to, but clearly your idea of pressurizing with o2 and shaking will work (although you might want some industrial paint shakers for it)
 
You know, I searched that book and missed that when trying to get some answers before I posted this thread. Sure enough, I went back and checked and... page 78 more than half-way down is the answer I was looking for. Thanks for the info Bok. I had, I guess, not retained that bit of info while on the throne a couple of days ago. My book mark is on page 94, lol.
 
I'm reading the Yeast book currently and just ran across something relevant. "Filling the headspace of the fermentor and shaking vigorously can result in dissolved oxygen levels past 10 ppm, but once you have bottled oxygen, it is much easier to use a sintered stone"

So no idea what PSI to go to, but clearly your idea of pressurizing with o2 and shaking will work (although you might want some industrial paint shakers for it)

Good to see an anser to that. I had some rough calculations showing ~15ppm from regular headspace, non-pressurized, but I had a ton of bad assumptions in there.

Pressure to ppm is linear, so you should be able to adjust your pressurization and get fairly exact ppm numbers.

I would guess that you don't have to shake like crazy, you're not tryign to put 30psi in there, a couple of good shakes to get her started, and then just standard absorption plus yeast at the surface would finish it off I think.
 
That's what I am thinking kaiser423. Talk about an easy beer. No chill, pitch with the throw of a tap handle, and then fill the head space and shake a couple of times. Wait till I see pressure and set the valve for the trip to FG.
 
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