How much headspace is needed when using a corny keg as a fermenter?

[psehorne]

I have always used a carboy or my (plastic) conical for fermenting. Today I prepared a corny keg for fermenting. I installed a tr-clamp lid with a 15 PSI pressure relief valve. I also have a pressure gauge that I can install on the gas in port. How much headspace is needed when using a corny keg as a fermenter?

Thanks,
Paul

 

[lumpher]

You'll get different answers on this, but from what I've read and done, since I keg-ferment, 4.5 gallons in the keg is about right for me.

 

[mashdar]

FWIW, you should have one device for pressure control, and a second for emergency pressure relief. Does your lid have both?

I feel best with 4 gallons in a keg, but that's probably conservative for normal yeasts.

 

[psehorne]

You'll get different answers on this, but from what I've read and done, since I keg-ferment, 4.5 gallons in the keg is about right for me.

Thanks

 

[psehorne]

FWIW, you should have one device for pressure control, and a second for emergency pressure relief. Does your lid have both?

I feel best with 4 gallons in a keg, but that's probably conservative for normal yeasts.

The lid has one adjustable 'emergency' pressure relief valve, set at 15PSI. And I have a pressure gauge (for monitoring) attached to the gas in port. But no pressure control device.

Thanks for your input.

 

[mashdar]

The adjustable valve is your pressure control, and you have no emergency relief valve. "Emergency relief" is a backup function and not a type of device.

Your lid doesn't have a standard PRV in addition to the TC? E.g.
https://www.brewhardware.com/product_p/cornylidtc.htm

You can decide what risks to take, but a keg rated 130psi makes for a very big bang when it ruptures.

(I take it you're using the Spike valve, which they claim is both a floor wax and a dessert topping.)

 

[Yesfan]

I do no more than 4 gallons in my corny kegs. For my converted kegs I did:

1) added a floating dip tube with filter *
2) Swapped the grey prv with a red one (35psi)
3) Added a kegland spunding valve to my keg's gas post set at 15psi.

* On my floating dip tube, sometimes they may stick to the side or ride high enough above the wort to where I'm pulling co2 instead of beer during dispensing or transferring. I added some weight to the stainless float by using a spare 1/2" stainless washer. This seemed to work on my recent batch.

Another thing, if you're transferring to a keg with a floating dip tube, those filters will clog the line if the beer is a heavy hopped one. You don't really need a filter on a floating dip tube in a dedicated serving keg. Imo, it's better to have those filters only on the fermenting vessel or if that vessel is used for both fermenting and serving.

 

[mashdar]

PS it looks like you could add a safety device to the gas post and use a duotight gauge: https://www.morebeer.com/products/b...ng-prv-integrated-pressure-gauge-030-psi.html
There are some pretty good duotight-compatible gauges, including a digital one from kegland.

edit: I'd throw a red (35psi) PRV on there, or maybe green (65psi) if you plan to spund over 25~psi.

 

[Ramjet]

I use a blowoff tube on the gas post for the first day and a half then put a spunding valve on set at 12 to 15 psi for lagers. I use the flot it 2.0 floating dip tube. Never had any problems.

 

[Ramjet]

Forgot to mention I put 4.5 gallons in the keg

 

[psehorne]

The adjustable valve is your pressure control, and you have no emergency relief valve. "Emergency relief" is a backup function and not a type of device.

Your lid doesn't have a standard PRV in addition to the TC? E.g.
https://www.brewhardware.com/product_p/cornylidtc.htm

You can decide what risks to take, but a keg rated 130psi makes for a very big bang when it ruptures.

(I take it you're using the Spike valve, which they claim is both a floor wax and a dessert topping.)

Yes, that is the lid that I have. And yes, I really don't have an emergency valve. I was calling the adjustable valve 'emergency' . This if the valve I have https://www.amazon.com/dp/B0CLK8XBP9?ref=ppx_yo2ov_dt_b_fed_asin_title&th=1

I also connected a pressure gauge to the gas in port.

 

[psehorne]

I do no more than 4 gallons in my corny kegs. For my converted kegs I did:

1) added a floating dip tube with filter *
2) Swapped the grey prv with a red one (35psi)
3) Added a kegland spunding valve to my keg's gas post set at 15psi.

* On my floating dip tube, sometimes they may stick to the side or ride high enough above the wort to where I'm pulling co2 instead of beer during dispensing or transferring. I added some weight to the stainless float by using a spare 1/2" stainless washer. This seemed to work on my recent batch.

Another thing, if you're transferring to a keg with a floating dip tube, those filters will clog the line if the beer is a heavy hopped one. You don't really need a filter on a floating dip tube in a dedicated serving keg. Imo, it's better to have those filters only on the fermenting vessel or if that vessel is used for both fermenting and serving.

Thank you for your input. I too added a floating dip tube with filter, and I plan on using the keg for both fermenting and serving.... at least initially, until I evaluate the setup.

 

[psehorne]

PS it looks like you could add a safety device to the gas post and use a duotight gauge: https://www.morebeer.com/products/b...ng-prv-integrated-pressure-gauge-030-psi.html
There are some pretty good duotight-compatible gauges, including a digital one from kegland.

edit: I'd throw a red (35psi) PRV on there, or maybe green (65psi) if you plan to spund over 25~psi.

Thanks for the link to the adjustable valve and gauge on the gas in connector. The one I was looking at last night is out of stock, and I intended to look for others today.

 

[psehorne]

PS it looks like you could add a safety device to the gas post and use a duotight gauge: https://www.morebeer.com/products/b...ng-prv-integrated-pressure-gauge-030-psi.html
There are some pretty good duotight-compatible gauges, including a digital one from kegland.

edit: I'd throw a red (35psi) PRV on there, or maybe green (65psi) if you plan to spund over 25~psi.

Thanks, I did not know about the red and the green PRVs. I plan on spunding at no more than 15 PSI.

 

[psehorne]

I use a blowoff tube on the gas post for the first day and a half then put a spunding valve on set at 12 to 15 psi for lagers. I use the flot it 2.0 floating dip tube. Never had any problems.

I've been thinking about how to use a blow-off hose for the first day or so.

How do you use a blow-off hose on the gas port? Have you removed the poppet valve, or do you have a PRV upstream of the hose?

I also have a lid with the PRV drilled out leaving a hole ~7/8"diameter where I can use a bung and airlock. I could probably use that hole with a suitable size hose for a blow-off. It's not large enough for a standard size blow-off hose. I think a hose of 7/8" O.D. would not be prone to clogging.

 

[Broken Crow]

Since you have the TC lid, you could always just use a TC barb for the vigorous phase of primary, avoid gunking up your gas post, and switch it out when fermentation slows down. https://www.brewhardware.com/product_p/tc15hb58el.htm
You might find this recent thread useful:
https://www.homebrewtalk.com/threads/keg-fermenting.733781/

 

[psehorne]

Since you have the TC lid, you could always just use a TC barb for the vigorous phase of primary, avoid gunking up your gas post, and switch it out when fermentation slows down. https://www.brewhardware.com/product_p/tc15hb58el.htm
You might find this recent thread useful:
https://www.homebrewtalk.com/threads/keg-fermenting.733781/

Great suggestion. I found a 90 elbow with 1" barb; so I should be able to use my existing blow-off hose.
Thanks.

 

[9Kegs]

I ferment in 15.5 gallon torpedo kegs with 12 gallons of wort. Never had an issue with anything coming through blowoff tube. I recently experimented maxing out starting volume with 14.5 gallons. In this case I brewed a lager (less active fermentation) and I used Fermcap and still had nothing coming through blowoff tube. One additional note: No impact on harvesting and reusing yeast with Fermcap.

 

[psehorne]

Nice setup. I brew with my BrauMeister 20L. I'm sticking with 5 gal batches.

 

[waynetempro]

Here’s that I’ve done with good success. 4.8-4.9 gallons in a standard ball lock keg with a spunding valve set at 14psi. I used US05 and had no problems with. Some other yeasts will have a huge krausen and will need a lower fill volume like 4.5 gallons.

 

[psehorne]

Here’s that I’ve done with good success. 4.8-4.9 gallons in a standard ball lock keg with a spunding valve set at 14psi. I used US05 and had no problems with. Some other yeasts will have a huge krausen and will need a lower fill volume like 4.5 gallons.

Thank you, waynetempro. Good info.

For my next two brews I am also using Safale US-05

Last weekend on Saturday I brewed Irish Stout and fermented (in a carboy) with S-04... VERY active and definitely needed a blow-off for a couple of days. It nearly quit perking the air lock after only three days.

On Sunday I brewed a Amber Ale with Wyeast 1056.... much tamer and just yesterday (after six days) quick perking.

 

[mac_1103]

Your lid doesn't have a standard PRV in addition to the TC? E.g.
https://www.brewhardware.com/product_p/cornylidtc.htm

Yes, that is the lid that I have.

That lid does have a standard PRV in addition to the TC.

 

[psehorne]

That lid does have a standard PRV in addition to the TC.

Yes. Glad you pointed that out. I had forgotten. At what pressure does it release?

 

[mac_1103]

At what pressure does it release?

The standard grey/white inserts release at 100 PSI. You can replace the insert with one that will release at a lower pressure if you want to: green = 65 PSI, red = 35 PSI, yellow = 17 PSI.

 

[Ramjet]

I've been thinking about how to use a blow-off hose for the first day or so.

How do you use a blow-off hose on the gas port? Have you removed the poppet valve, or do you have a PRV upstream of the hose?

I just use a gas ball lock connector and a length of hose with no fitting on the opposite end into a jar of Starman. I do not remove the poppet valve.

 

[VTMongoose]

I pressure ferment in Oxebar kegs, therefore I have visibility of the krausen itself and I can tell you that with or without fermcap (although obviously it's safer to put a few drops in), the krausen height only reaches 1/2" at the absolute maximum under pressure with any standard lager yeast. In other words, you can really cram a lot in there without any worry of it reaching your gas post as long as you spund from day 1 and pitch low.

 

[psehorne]

I pressure ferment in Oxebar kegs, therefore I have visibility of the krausen itself and I can tell you that with or without fermcap (although obviously it's safer to put a few drops in), the krausen height only reaches 1/2" at the absolute maximum under pressure with any standard lager yeast. In other words, you can really cram a lot in there without any worry of it reaching your gas post as long as you spund from day 1 and pitch low.

I have never run across those Oxebar kegs.... TNX

 

[psehorne]

I just use a gas ball lock connector and a length of hose with no fitting on the opposite end into a jar of Starman. I do not remove the poppet valve.

Oh! I thought you meant you put a hose on the ball lock post itself. Thanks for explaining....

 

[VTMongoose]

I have never run across those Oxebar kegs.... TNX

You can get them from Morebeer. They are insanely cheap and free shipping as well. I love them. They are incredibly easy to use and clean compared to standard corny kegs, and best of all they come standard with floating diptubes WITH a filter in the event you dry hop in keg.

https://www.morebeer.com/products/o...one-dip-tube-filter-prv-carbonation-caps.html

 

[psehorne]

You can get them from Morebeer. They are insanely cheap and free shipping as well. I love them. They are incredibly easy to use and clean compared to standard corny kegs, and best of all they come standard with floating diptubes WITH a filter in the event you dry hop in keg.

https://www.morebeer.com/products/o...one-dip-tube-filter-prv-carbonation-caps.html

Wow! What a deal, and includes a floating dip tube. Just added one to my cart.
Thanks,