Spunding and Fermentation

Nola_Brew

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Just purchased a blowtie diaphragm spunding valve that I want to use to naturally carb my beers.
I've done a good bit of reading on the process and I think I understand the process.
I'm considering two options:
1) ferment in my brewbucket for 3-4 days then transfer to a keg and install the spunding valve. Unsure of what pressure I need to aim for. If I did it this way I would have to dry hop in a keg. I also have a clear beer draught system that I will use in my serving keg and also a similar device to use in the keg I will be fermenting in.

2) ferment in a keg from the beginning using a blow off tube for the first 3-4 days of fermentation then switch to the spunding valve at a set PSI.

What I'm trying to determine is what pressure do I need to set the valve to. Would it be 12-15 PSI while there is still some fermentation still going on or would I go with 20-30 PSI? Once fermentation is complete, what PSI do I need to aim for to achieve 2.5 volume? I know there is a chart on the web that shows what PSI to use at a given temp. Just trying to figure out what pressure to use at the end of fermentation and when fermentation is over.

Wanting to see the process of others who ferment under pressure and naturally carb without having to use sugar.

Another question is I normally cold crash before transferring to a serving keg. When using the spunding valve and during the temp drop will the pressure in the keg increase?

Finally, I'm also considering getting a Kegmenter to use instead of fermenting in a corney. Reason is if I use a corney, volume will only be 4 gal of finished product. Using the Kegmenter will allow me to brew my usual volume so I would have a full 5 gallons.
Looking for thoughts from anyone who has a Kegmenter. I like the fact it has a TC fitting including. Only downside I can see is there is no way to accurately measure temp. Would have to use one of those stick on thermometer's.
 
I'm in the same spot as you. I'm switching over to fermenting in kegs. I converted a 1/4 barrel Sanke to a fermenter and I'm now learning how to use it. I first started out just fermenting and doing closed transfers, but I want to try fermenting under pressure.

It was a little tough going from carboys to kegs. The first beer I fermented was a Maibock fermented in a Corny keg and it turned out fantastic. The beers seem to be cleaner and I'm wondering if it's from hydraulic pressure since the kegs are taller and skinnier than carboys. That's why I want to try fermenting at 5 psi to see if my lagers will be cleaner. I never transfer to a secondary to avoid oxygen ingress. A floating pick up helps to keep the beer clear when I transfer it to a serving keg.

Carbonating with spunding will take some trial and error, that will be the last hurdle I have to overcome.

The Kegmenter is similar my setup and it looks like it would work well. As far as cold crashing, the pressure drops as the temperature drops. The CO2 is absorbed and the beer contracts as it cools. I pressurize to at least 5 pounds and sometimes have to add more 24 hours after crashing.

Dry hopping is another problem, it's hard to dry hop in any vessel without adding oxygen. I inject CO2 at the bottom of the fermenter as I add the hops. That mixes the hops in and scrubs the beer of oxygen from the hops and keeps a positive pressure in the vessel, at least that's the idea.

Good luck, I hope it works out for you. You're on the cutting edge of homebrewing. Kind of fun, aint it?
 
My thoughts and only thoughts not personal experience is if fermenting under pressure why not "daisy Chain" a gas line from gas outlet on preassure ferm vessel to receiving keg (gas disconnect) filled with starsan and use fermentation to push put starsan into another keg via liquid side or just into a bucket. I'm wondering if you could insert future dry hops into keg canister in recieving keg once star san is pushed out. I know this will introduce o2 once again but maybe continuing fermentation will purge what o2 was in the hops and canister so that once beer is finished fermenting you can then transfer beer from pressure ferm vassal into receiving keg with hops purged and ready to go?
 
I was thinking to ferment under pressure in the 5-8 PSI range. Whether I ferment in a corney or get a Kegmenter, my plan is to transfer to a serving keg when fermentation is complete using a jumper line. The only time I see where oxygen will be introduced is when I dry hop but I don't see that as a problem if I purge the keg or fermenter with co2. I'm unsure if dry hopping will take place in the fermenter or keg- may try both ways to see which I prefer.

If I add DH at day 3 or 4 of fermentation there would still be some activity to avoid any issues with oxygen.

I may also eliminate dry hoping completely and add a massive WP addition and see how that works. This way I would not have to open the fermenter or keg so no oxygen will be introduced.

As for spunding, not real sure how I will go about it just yet. Trial and error I suppose.
 
I forgot to mention, the temp probe can be taped to the fermenter. Since it’s stainless it will transfer the temp of the wort pretty well. I also tape cardboard over the probe to insulate it from the air in the chamber, crude but effective.
 
Set the pressure based on temperature just as you would if you were force carbing. Just use the calculator on the site here. For 2.5 volumes at 68 degrees you need 27.6 psi.
I close off my unitank when it'd 3-5 points short of FG. It's important that you don't use up all the sugars before you close off. You won't be able to just schedule it out and guess...you'll have to check gravity to be sure. If you transfer, you run the risk of stalling so be sure you catch it just at the end of active fermentation before the yeast really starts to drop. if you're worried about loss, finish the fermentation completely, including dry hopping and then transfer to a keg with the proper amount of priming sugar and set your pressure. I don't think that yields quite the same results as capping the fermentation, but it should be very close.
 
Set the pressure based on temperature just as you would if you were force carbing. Just use the calculator on the site here. For 2.5 volumes at 68 degrees you need 27.6 psi.
I close off my unitank when it'd 3-5 points short of FG. It's important that you don't use up all the sugars before you close off. You won't be able to just schedule it out and guess...you'll have to check gravity to be sure. If you transfer, you run the risk of stalling so be sure you catch it just at the end of active fermentation before the yeast really starts to drop. if you're worried about loss, finish the fermentation completely, including dry hopping and then transfer to a keg with the proper amount of priming sugar and set your pressure. I don't think that yields quite the same results as capping the fermentation, but it should be very close.

Thanks for the info. I'll have to get in the habit of checking gravity at day 2 and 3 of active fermentation so i can see where it's at. I usually don't check until i feel fermentation has finished.
Don't want to go the priming sugar route- want to try and do this naturally.
 
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Don't want to go the priming sugar route- want to try and do this naturally.
It'll essentially be natural carbonation if you have to prime, but it really is simple and efficient if you can cap the fermentation at the right time and get it done that way.
 
Just a note, I had a chat with a very small local brewer a couple years ago. He used spunding for carbonating and canned and kegged his beer. To know when to start to pressurized he would pull a sample from each batch, inoculate with yeast and ferment the test batch clear out. That would give him exact final gravity so when the larger batch, which fermented a bit slower, reached proper gravity points for calculated carbonation he would begin pressurizing ferm tank. Hope this helps!
CHEERS
 
It'll essentially be natural carbonation if you have to prime, but it really is simple and efficient if you can cap the fermentation at the right time and get it done that way.
For the batch I will try to naturally carbonate FG is estimated to be 1.012. At day 2 or 3 of fermentation I'll pull a sample and if it's at 1.017 I'll switch to the spunding valve.
This will be trail and error for me so hoping I can at least get it right or close to right on the first try. It will be probably 2-3 weeks before I brew this batch so I'll have a bit more time to research and get my plan down.
 
Most of the stuff I've seen suggests 1P from final gravity. That's about 4 gravity points. Head First's suggestion about a fast ferment test is useful but since FG isn't critical to the process unless it stalls short, I find that estimating does just fine. Since I don't have a fully adjustable spunding valve and my pressure relief valve is set a little short of the exact pressure I'd need at 68F (my usual finishing temp). I tend to err on the early side and just let it run it's course.
Don't forget that you have to maintain pressure during transfer. You'll need to make a jumper hose with two "out" ball lock QDs (yes, fill the receiving keg through the dip tube). And don't reset the pressure as you crash and chill, By the time it's cooled down the pressure will drop on it's own. If you've calculated properly, you should be right at the proper pressure for the final temp. If it's a little flat or needs a little "topping up" with Co2, just pressure the keg to the proper PSI and check several times over a few days to be sure it stabilizes as the additional CO2 enters into solution.
 
Most of the stuff I've seen suggests 1P from final gravity. That's about 4 gravity points. Head First's suggestion about a fast ferment test is useful but since FG isn't critical to the process unless it stalls short, I find that estimating does just fine. Since I don't have a fully adjustable spunding valve and my pressure relief valve is set a little short of the exact pressure I'd need at 68F (my usual finishing temp). I tend to err on the early side and just let it run it's course.
Don't forget that you have to maintain pressure during transfer. You'll need to make a jumper hose with two "out" ball lock QDs (yes, fill the receiving keg through the dip tube). And don't reset the pressure as you crash and chill, By the time it's cooled down the pressure will drop on it's own. If you've calculated properly, you should be right at the proper pressure for the final temp. If it's a little flat or needs a little "topping up" with Co2, just pressure the keg to the proper PSI and check several times over a few days to be sure it stabilizes as the additional CO2 enters into solution.
I have the jumper hose I made and have a blowtie spunding valve (kegland). I'll also be using floating dip tubes in fermenting keg and also serving keg.
Also, when you hit 3-5 points from FG and close off your Uni, do you just allow the pressure to build? I'll probably ferment between 62-65 degrees. According to the chart using 65 degrees as the ferm temp, I would need 27.4 PSI to achieve 2.6 vol. Would there be sufficient PSI building from closing off with 3-5 points to go?
I also plan on cold crashing prior to transferring to my serving keg. I usually get the temps down to 40-45 then transfer. At that temp, I'll adjust my spunding valve and follow the chart you linked.
 
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Just throwing it out there on the hypothetical from what ive seen on the Vlogs online some HB's when preassure fermenting via spunding have just set the the spunding device to fermentor or ( receiving keg) right from the get go. So maybe this would be.an easy approach if you didn't wanna hang around in a day or two testing fermentation gravity to decide if a few points off final gravity to start spunding.

Also sounds like spunding and this Tilt type hydrometers go hand in hand.
Cheers really enjoying this thread.
 
Just throwing it out there on the hypothetical from what ive seen on the Vlogs online some HB's when preassure fermenting via spunding have just set the the spunding device to fermentor or ( receiving keg) right from the get go. So maybe this would be.an easy approach if you didn't wanna hang around in a day or two testing fermentation gravity to decide if a few points off final gravity to start spunding.

Also sounds like spunding and this Tilt type hydrometers go hand in hand.
Cheers really enjoying this thread.
From what I've read, that can be done as you mentioned. Only issue is if you are tight on headspace then you could have blowoff gunk up the spunding valve. If there is sufficient headspace then I don't see that being an issue. I may try that if I get something larger than a keg to ferment in. For this batch I'll be brewing a 4.75 gal batch so I'm expecting 4.25-4.5 gal into fermenter. If it's closer to 4.25 gal then there should be sufficient room to allow for fermentation and should not have any issues with any blowoff. However if it's closer to 4.5 gal, for me, I would feel better using a blowoff tube for the first 2-3 days of active fermentation then switch over to the spunding valve.
 
At that temp, I'll adjust my spunding valve and follow the chart you linked.
Once you finish fermentation and start to drop temp, you won't need to make adjustments to your spunding valve. You'll be done with it. The pressure will drop as temp drops so the spunding valve just remains closed off. Once you're at FG and there's no more fermentation and no more CO2 production, the work of the spunding valve is finished - just remove it from the ball lock and leave the keg closed.
Also, when you hit 3-5 points from FG and close off your Uni, do you just allow the pressure to build?
Yeah...since my pressure relief valve maxes out at around 20, I just use that as a starting point. I can adjust it for less pressure but not more. I could just remove the PRV and close it off completely, but it's better to have some safety margin. When I start to drop temp, I just add a little CO2 to adjust pressure. At some point I'll invest in a properly adjustable spunding apparatus, but this has been effective and hasn't added any cost to my rig.
I'll probably ferment between 62-65 degrees. According to the chart using 65 degrees as the ferm temp, I would need 27.4 PSI to achieve 2.6 vol. Would there be sufficient PSI building from closing off with 3-5 points to go?
Should be fine according to my less-than-exhaustive research. ;) Since you have the pressure regulated in such a way that it'll max out at whatever you're spunding valve is set at, you won't have any problem closing off early. With Lagers there may be some issue with holding excess sulfur in suspension but it'll gas off eventually with a few purges in the keg.
 
For corny kegs, I've been playing with altering red (35psi) pressure relief valves and modifying the spring (actually cutting new springs from 24" lengths) to attain different pressures. Currently using a 13psi for fermentation under pressure. Can't yet provide results.
 
For corny kegs, I've been playing with altering red (35psi) pressure relief valves and modifying the spring (actually cutting new springs from 24" lengths) to attain different pressures. Currently using a 13psi for fermentation under pressure. Can't yet provide results.
Yeah, interested in what you come up with.

Right or wrong (but works great for me) I have been giving my fermentation about 24 hours to ferment freely. Then I set my Blowtie spunding valve to 15 psi and let it go till done. I've been doing a pressure transfer then attaching the newly filled keg to my regular serving pressure which is about 14 psi. It's drinkable right away but much better and perfectly carb'd up and creamy within a few days. The creamy heads I've been getting are similar and remind me of bottle conditioning.
 
Yeah, interested in what you come up with.

Right or wrong (but works great for me) I have been giving my fermentation about 24 hours to ferment freely. Then I set my Blowtie spunding valve to 15 psi and let it go till done. I've been doing a pressure transfer then attaching the newly filled keg to my regular serving pressure which is about 14 psi. It's drinkable right away but much better and perfectly carb'd up and creamy within a few days. The creamy heads I've been getting are similar and remind me of bottle conditioning.
Yeah I think the bubbles are smaller and tighter.
 
I'm on the fence here. Since i returned the Fermzilla, been contemplating getting the snub nose or the Kegmenter. The issues I had with the Zilla has prevented me from pulling the trigger on the snub nose version. With the snub nose the only thing I will need to be concerned with is the lid. I really do not like the gaskets on the lid of the snub nose/Zilla and I dont want to be replacing gaskets every year because they get worn out. But I really like the Kegmenter, which is about $50 more.
I want to be able to naturally carb as Thunderwagn does and do pressure transfers. I'll continue to talk my self out of either one until Black Friday. Maybe the Kegmenter will be reduced or something at Morebeer and will make my decision easier.
 

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