Spunding PSI

[Brews and Blues]

Background on this brew: I am fermenting and serving a black IPA in one keg. I used a blow off tube until day 7, which is when i added the spunding valve. My plan is to spund until fermentation is complete and i hook up to co2 and throw in the kegerator. Today is day 9 and the brew has been temp controlled at 63F - yeast US-05. My question is, what PSI do i want my spunding valve at. The one i have is adjustable. It has slowly crept up to about 15 PSI currently. Not sure where that should be at. This is my first time using it and i have no idea what my goal PSI should be.

 

[odie]

I'm guessing around 25-30 PSI at your current temps. Once it's totally done fermenting and you move it to the kegerator, the psi is gonna drop as it cools down. Once it's cold crashed the keg psi should be close to what your regulator is already set at for serving.

 

[odie]

I'm currently doing my first single keg ferm & serve. A steam beer ferming at 55-60 so I'm targeting 20 psi until it finishes.

But I don't have a spunding valve yet. I just put a press gauge on the gas post and bleed the PRV to 10 psi every so often and let it build again. Once it stops "rebuilding" I'll know it's done fermenting.

 

[Dustin_J]

You can use a chart (Keg Carbonation Chart) or calculator (Keg Carbonation Calculator - Brewer's Friend) to get the correct PSI given the temp and desired volumes of CO2. Keep in mind that you need ~ 1 point residual SG for each ~.5 volumes of CO2 you want (beyond what's soluble/already dissolved via fermentation at the given fermentation temp).

 

[Dland]

I usually run my spunding up to around 30 PSI in the 60F range. This gives me around 12 PSI at 30F when it is crashed.

 

[Brews and Blues]

Thanks everyone!
So if my psi is low, the only effect will be that i will need additional efforts from the co2 to get my beer carbonated correct?

 

[Dland]

That's right, you just have to partially force carb up to desired levels if you undershoot spunding pressure. (or I suppose add sugar, but would avoid this as is an oxidation risk at this point).

 

[Jim R]

Why wouldn’t you pressure ferment from day 1 if you have a spunding valve and a fermenter that holds pressure?

 

[VikeMan]

Why wouldn’t you pressure ferment from day 1 if you have a spunding valve and a fermenter that holds pressure?

If you mean ferment under high pressure from day 1, I wouldn't do that because it supresses (slows) yeast actvity. I "spund" from the beginning, but at only about 2 PSI gauge.

 

[Dr_Jeff]

Why wouldn’t you pressure ferment from day 1 if you have a spunding valve and a fermenter that holds pressure?

I do, 8-10 pounds on day one and slowly turn it up over the duration until it gets to 30, and crash cool from there.

 

[Golddiggie]

So far I've set my spunding valves to 14-15psi from the start and let things ride. Solid results for those batches.
Next two batches, I plan to set the spunding valves at a lower limit and see what that gives me. One is another stout and the other is a best bitter. Probably somewhere in the 5-10psi limit (haven't decided just yet, could be different for the two recipes).
IMO, not having to change out a blow-off assembly for the spunding valve is a GOOD thing. One less time you're opening things up to risks.

 

[Dr_Jeff]

I've had a lively fermentation several times and had yeast blowing out of the vents on the spunding valve, what a mess.

 

[Golddiggie]

I've had a lively fermentation several times and had yeast blowing out of the vents on the spunding valve, what a mess.

What spunding valve was that? How much headspace did you have in the fermenter?

I've put almost 7 gallons into a 7-3/4 gallon fermenter without any issue at all with the blowtie I was using. Going to the SSBrewTech setup for the conicals. Conical capacity is 14 gallons and I don't expect to put more than about 10-11 gallons into them (for 9 gallon to keg/can batches).

 

[DuncB]

I use this calculator.
https://drhansbrewery.com/beercarbonationcalculator/
I start with about 10/15 psi for clean non expressive ferments and leave it open or just a couple of psi if I want the yeast to do it's thing, then turn it up as the krausen falls. I aim to have enough pressure in the fermenter for my serving vols at the end of ferment or a day or two before. Pressures can be quite high with kveik ie 35 psi at 30 celsius for 2.3 vols. I also purge the keg and fill it to that pressure so that when I do closed transfer and the fermenter pressure has dropped during the cold crash the keg pressure excess nearly runs the whole transfer.
@VikeMan I accidentally sealed the fermenter from day one ( due to a non return ball lock connector I fitted on my spunding valve - I hadn't thought it thru) on a wheat beer it was fermenting like crazy on day 5 when I checked it and was at 35 psi.
Also the yeast seems to be going fairly well in this video



But the pressure does affect how the yeast works but perhaps not that much in terms of speed, I've not done a side by side test though.

 

[Dland]

No doubt, there are many ways to spund. Some here seem to be fermenting at pressure and will of course end up with a "spund carbonated" product, if all goes well.

What has worked out for me best is to rack from primary to kegs when there is still a little fermentation to go,( & do D rest at same time if a lager). This is admittedly with the luxury of conical fermentor dump & rack valves, plenty of kegs, etc.

I'm sure there are a lot of ways to get good results for experienced brewers who know their gear. You'll know when your have got spunding right with your rig when you get good results, and it hardly takes any extra effort.

 

[Dr_Jeff]

What spunding valve was that? How much headspace did you have in the fermenter?

I've put almost 7 gallons into a 7-3/4 gallon fermenter without any issue at all with the blowtie I was using. Going to the SSBrewTech setup for the conicals. Conical capacity is 14 gallons and I don't expect to put more than about 10-11 gallons into them (for 9 gallon to keg/can batches).

15.5 gallon fermenter, Belgian Quad - WLP-530 yeast, big pitch (yeast cake from a wit) likely 11-11. 5 gallons in 64=65 degrees or so if I remember correctly, it's been a while. (4 years ago, maybe)

 

[Jim R]

I start with about 10/15 psi for clean non expressive ferments and leave it open or just a couple of psi if I want the yeast to do it's thing, then turn it up as the krausen falls. I aim to have enough pressure in the fermenter for my serving vols at the end of ferment or a day or two before. Pressures can be quite high with kveik ie 35 psi at 30 celsius for 2.3 vols. I also purge the keg and fill it to that pressure so that when I do closed transfer and the fermenter pressure has dropped during the cold crash the keg pressure excess nearly runs the whole transfer.

+1. This is almost exactly what I do and it works perfect every time.

 

[Golddiggie]

15.5 gallon fermenter, Belgian Quad - WLP-530 yeast, big pitch (yeast cake from a wit) likely 11-11. 5 gallons in 64=65 degrees or so if I remember correctly, it's been a while. (4 years ago, maybe)

Still don't see what spunding valve you used. But judging by the time frame, it's not one that I've used. So far I've used both Blowtie models and will be using the SSBrewTech TC connected model. I'll probably give one of the Blowtie setups to my nephew if he's going to brew with friends out in the Chitcago area (he's going there since his fiancee is going to grad school out there). I'll keep the other in case I do something in one of my kegmenters (instead of the conicals).

 

[DuncB]

Any spunding valve is better than that all metal one they used to sell ( I had to modify mine seen on the right in this picture). Required the skills of a safe cracker to set that and even then was unreliable.

 

[hottpeper13]

Vikeman, does that low pressure(2 psig) suppress the krausen enough for a 10.5 gal batch in a 13.2 gal conical? I'm getting the Fermzilla on Tues and use 2565 as a house yeast and use a blowoff every time.
Also wondering if using the capture CO2 method (pushing 5 gal of sanitizer into another keg) is enough pressure to suppress the krausen.

 

[VikeMan]

Vikeman, does that low pressure(2 psig) suppress the krausen enough for a 10.5 gal batch in a 13.2 gal conical?

It doesn't, I suspect, do much at all to supress krausen. If I'm worried about my combination of gravity, yeast strain, fermentation temp, batch size, and headspace size causing a blowoff, I use a blowoff for a couple days, then switch to the valve. But that's maybe 5% of my batches.

Also wondering if using the capture CO2 method (pushing 5 gal of sanitizer into another keg) is enough pressure to suppress the krausen.

I don't use the sanitizer method. But I think it would depend on how much pressure is needed to push it in your system.

 

[ChiknNutz]

Here is a thread I started on the subject. The first few posts of mine show my naivety in the process. Post #27 is generally how I go about it now with good results.
Spunding for Dummies

 

[odie]

Why wouldn’t you pressure ferment from day 1 if you have a spunding valve and a fermenter that holds pressure?

The OP was fermenting in a keg. That is why. Minimal head space. Maybe 1/2 a gal. There will be blow off...or blow out :O

I'm attempting to ferment in the serving keg as well. I got my full 5 gal of wort plus one pint in there. The first couple of days it's gonna have some blow off that i would not want in my valve and gauge. When the bubbling slows down is when I'll cap it and let it pressurize as it finishes.

 

[Dr_Jeff]

Still don't see what spunding valve you used.

I used on that I had built, from an adjustable PRV, a gauge and a few fittings connected to a ball lock connector.

 

[Golddiggie]

The OP was fermenting in a keg. That is why. Minimal head space. Maybe 1/2 a gal. There will be blow off...or blow out :O

I'm attempting to ferment in the serving keg as well. I got my full 5 gal of wort plus one pint in there. The first couple of days it's gonna have some blow off that i would not want in my valve and gauge. When the bubbling slows down is when I'll cap it and let it pressurize as it finishes.

I've never understood the desire to ferment in serving keg. You'll always be down a good amount of volume due to the blowoff, or headspace needed, plus the yeast sediment in the bottom. For a long time I did ferment in sanke kegs (or kegmenters I guess they call them these days). Pressure transfer to serving kegs, with those being full.

 

[odie]

I've never understood the desire to ferment in serving keg.

I never knew it was a thing.

There are many way to brew and ferment...everyone has their own reasons...and their own objectives.

Depending on one's own system and methods, they may or may not have the same issues of volume, headspace, blowoff and yeast that you experienced.

 

[Golddiggie]

I never knew it was a thing.

There are many way to brew and ferment...everyone has their own reasons...and their own objectives.

Depending on one's own system and methods, they may or may not have the same issues of volume, headspace, blowoff and yeast that you experienced.

True... I've found that fermenting under pressure I can get 7 (or a little more) gallons in the tall 1/4 bbl kegmenter and NOT need a blowoff setup. Previously, if I didn't leave a gallon of head space, I'd need to have the blowoff setup in place right after pitching yeast.

I need to find new homes for most of my kegmenters.

 

[Brews and Blues]

I've never understood the desire to ferment in serving keg. You'll always be down a good amount of volume due to the blowoff, or headspace needed, plus the yeast sediment in the bottom. For a long time I did ferment in sanke kegs (or kegmenters I guess they call them these days). Pressure transfer to serving kegs, with those being full.

I just did a full 5 gallon batch and didn't have one drop come through my blow off tube. There was plenty of headspace at least with the US-05 and i had good fermentation.
The reason why i want to ferment and serve in the same keg is so i don't have to transfer. Less cleaning and less work.
As far as the sediment, i am using a floating dip tube so it shouldn't be an issue until the keg blows.

 

[Golddiggie]

Closed system transfers eliminates any potential issues from that. Moving off the yeast cake also eliminates needing to install floating dip tubes. You're also limited in what size batch you can ferment in each vessel. I have kegmenters sized from about 3-1/2 gallons up to 15-1/2 gallons. We did a 12 gallon (into carbonating/serving kegs) batch in the 15-1/2 gallon kegmenter last.
With my new conicals (getting their first batches Sunday and then sometime next week) I'll have even more options and be able to fine tune things easier. Dry hopping is going to be easier and O2 free. I'll be carbonating in those before moving some to serve on tap and the rest will go directly into cans.

Did you use a 5 gallon keg for that 5 gallon batch? Or did you use one of the 6 gallon Torpedo kegs to get 5 gallons out??

 

[odie]

I've got 2 beers going right now in kegs. 5+ gal of wort in each 5 gal corny (they hold 5.5). Nothing came out the blow off except bubble and a little foam. the jar the tube was in did not gain any volume. Both have slows down and the blow off tube was replaced by the gas post.

My old methods the wort is screened so there is only 1/2 of trub or yeast at the end of fermentation. I expect my first pint to be the yeast harvest followed by hopefully clear beer. If not, then a floating dip tube will be my next modification.