Corny keg question

[Just_another_drunkard_666]

So I've been brewing for a few years and kegging for a few months. I'm currently heating strike water for a beer I plan to ferment in a corny keg. My question is this: for the keg I'm intending to use, I need to use co2 to properly seal it. But I'm using a blowoff style setup during fermentation. So once I hook up my tube all co2 inside the keg will escape. Does the lid maintain a seal after that pressure is released? I mean, obviously it works in the kegerator but it's still sitting at 12 psi. Just a little confused I suppose.

 

[GilSwillBasementBrews]

Mine do. But I know some people have had issues sometimes with them not sealing without pressure. I would think if your seal is in good condition and the top is not damaged in any way you should be fine.

 

[lablover]

Mine hold just fine without getting a pop of CO2 like some people say. I do replace my lid o-rings every few years and my kegs are in good shape. If you want to be sure, just use a little keg lube on the o-ring before you seal it up.

 

[micraftbeer]

You could also get a spunding valve if you're concerned and put this on your gas post. Set it to like 2 psi or something. You could also put your blow-off tube into a deep bucket of water. The further underwater your blow-off tube is, the greater the pressure. I guess like a poor man's spunding. This being said, I've never crunched any numbers to know if 12" of water vs. 3" of water is a significant pressure difference.

https://www.morebeer.com/products/blowtie-2-spunding-valve-complete-kit.html

 

[odie]

don't bother sealing the lid. the blow off tube is fine. once the blow off slows then replace the keg post and the lid should seal on it's own shortly, then spund to desired pressure.

Or you can skip the blow off tube and just let the keg seal on it's own and spund from the start.

Or you can replace the PRV with lower PSI ones and just let it be.

Many ways to do it.

I currently have 2 kegs going...no blow off and no spunding valve...both have 10 PSI PRV installed and gauges on the gas post to monitor. One keg is sitting at 20 psi and no krausen or anything is coming out the PRV, just CO2 venting. The other keg is a Hefe (explosive yeast) and is holding at 15psi with krausen coming out the PRV but should settle down shortly. Both kegs just sitting in the living room at 75 degrees. fermenting under pressure you can run higher temps.

 

[Just_another_drunkard_666]

Thanks for the advice. I have it blowing off right now, will probably try and switch to spunding when it slows which is real soon because I'm fermenting with kviek at 85-90 degrees

 

[odie]

I've got a hefe going in the upper 70s with a 10 psi PRV. stays around 15psi. I just let it spund/blow off thru the PRV. Seems to be doing well. I just swapped the PRV out with a 30 psi PRV this morning to let it finish up.

 

[Just_another_drunkard_666]

This is the first I've heard of prv's with different tolerances. Haven't researched it much will definitely look into this

 

[odie]

This is the first I've heard of prv's with different tolerances. Haven't researched it much will definitely look into this

ebay or AliExpress (better). I bought some 10(blue), 15(purple) and 30(red) psi PRV valves. lighter springs and/or fewer coils. I ran some tests and they are all pop about 5-10 psi higher and then reset around +/- the rated psi. The original PRVs are around 100ish.

 

[cmac62]

ebay or AliExpress (better). I bought some 10(blue), 15(purple) and 30(red) psi PRV valves. lighter springs and/or fewer coils. I ran some tests and they are all pop about 5-10 psi higher and then reset around +/- the rated psi. The original PRVs are around 100ish.

I like this route, seems way easier than dealing with a spunding valve. I may have to look into the different PRVs. Thanks

 

[odie]

I just started using these. Think I'm gonna leave the 10 psi (blue) PRV valves in place for a few days. Then swap for the 30 psi (red) PRV as any remaining fermentation finishes up.

 

[cmac62]

I just started using these. Think I'm gonna leave the 10 psi (blue) PRV valves in place for a few days. Then swap for the 30 psi (red) PRV as any remaining fermentation finishes up.

I think that would be great for carbing. Of course you could just put the 100 PSI back in with a few points remaining and no harm no foul.

 

[odie]

Well, with the standard PRV back in then there is a good chance the keg will over carb. The 30-ish one is fairly close to target psi at fermentation temps to achieve close to desired volumes of CO2. So I can put it in the cellar and just forget it. it won't ever exceed too much. It's a lot easier to top-off the keg psi when time to serve than to try bleeding it off because it's too foamy.

 

[Dr_Jeff]

ebay or AliExpress (better). I bought some 10(blue), 15(purple) and 30(red) psi PRV valves. lighter springs and/or fewer coils. I ran some tests and they are all pop about 5-10 psi higher and then reset around +/- the rated psi. The original PRVs are around 100ish.

I've found the 30-35 red on AliExpress, could you provide a link to the 10 & 15 ?

Thanks
Jeff

 

[odie]

don't have a link but the seller was TWELVETAP Official Store

 

[Beekeeper]

https://www.aliexpress.com/item/100...g0o.store_pc_home.productList_339881277.pic_3

don't have a link but the seller was TWELVETAP Official Store

 

[Dr_Jeff]

don't have a link but the seller was TWELVETAP Official Store

Thx

 

[Jim R]

The PRV’s are a way to save a little money but it is really nice to have a good spunding valve long term. Not only can you much more accurately dial in the fermentation and carbonation pressures but you can use the output to purge kegs with fermentation CO2. I also use them when I do pressure transfers to minimize foaming by minimizing pressure differences between vessels. They are worth a little extra money.

 

[odie]

I do have a spunding valve but with 3 kegs fermenting right now...plus, if you get krausen in your valve it's a pain to clean it all out. PRV you just rinse.

a bunch of different ways to do it...I use several methods inter changeably