Can I get some advice on spunding

[bjhbrew]

Alright I’ve been thinking about this a lot so this’ll probably be a longer post. I recently bought the 35L snub nose fermentasaurus fermenter and I’d like to make use of its pressure rating. First off I’m hoping that using a spunding valve set low (maybe 5 psi) can help to keep the Krausen down so I can fill the fermenter pretty full (30L). Then I’d like to raise the pressure to carbonate naturally while limiting any o2 ingress. Pretty standard stuff so far but my final goal is to also use the co2 produced during fermentation to purge my serving keg so I’m wondering if it matters/makes a difference if the spunding valve goes between the vessels or after the serving keg? I attached a couple diagrams below to illustrate what I think are my options:

Option 1:

Jumper between the gas post of the fermenter to the liquid post of the serving keg. Put a typical spring and poppet style spunding valve on the gas post of the serving keg set to 5 psi and it’s ready to go

Pros:

No blow off liquid, airlock, or extra hose needed (less cleaning)
I can buy all the stuff at my LHBS

Concerns:

I’m concerned that 5 psi might not be enough to seal the lid which means the fermenter won’t get pressurized and krausen could get up in the jumper/serving keg.

I’ve heard that spring and poppet spunding valves tend to leak so I might have to keep a closer eye on this at the tail end of fermentation. I like to be pretty hands off and give plenty of time in primary 2 weeks plus so I’d rather not have to futz with it.

Option 2:

Use the kegland BlowTie spunding valve which allows tubing to be connected to the outlet. This way I can put the spunding setup directly on the fermenter and then route the gas that gets past the valve to purge the serving keg. A blow off tube or airlock would be needed on the serving keg but it would not be pressurized.

Pros:

The BlowTie is a diaphragm style valve so it’s supposed to be more accurate and shouldn’t leak.

Only the fermenter is being pressurized (I don’t know if that matters). With an airlock on the serving keg there is no chance of a leak causing o2 ingress.

Concerns:

Any possible blowoff going into the gauge and spunding valve.

I’m in Canada and the BlowTie and related parts are not available. I can order from MoreBeer and ship accross the border but obviously it’ll cost quite a bit more.

Just the need for an extra hose and container of sanitizer for an airlock.

So what say ye, wise brethren of the brew?

 

[Dland]

I'm less ambitious than you, I do not bother to scavenge the CO2, like to keep thing simple. I just closed transfer/rack to kegs when there is about .006-8 to go and spund in them. Almost all the trub is left behind in primary fermentor.

That way I can fully carbonate via spunding, typically around 30PSI at cellar/room temp works out to around 2.5 vols CO2.

When spunding/cellar conditioning is complete I crash kegs in fridge.

 

[501irishred]

I’ve been thinking about going this direction as well (take that as I have no clue). My plan was similar to your first sketch with the pressure valve on the output of keg. The only thing I’m thinking of adding is an isolation chamber, for any blowoff, between the fermenter and keg. A little more complexity but maybe a little more peace of mind.....

 

[ScrewyBrewer]

@bjhbrew I’m doing something similar to what you’re planning. My concern is trub or hop debris clogging the gas poppet causing the psi in the fermenter to get too high. But I’m not using the Co2 to carbonate the beer yet.

I did setup a BlowTie valve to use as a safety relief to prevent Co2 pressure spikes above 2-3 psi. That’s the maximum recommended pressure of the fermenter. In two weeks I plan to do my first pressure transfers using the setup.

Currently I have a Kölsch style beer fermenting with blowoff tubes coming off gas posts in the fermenter lids. No problems with this approach so far but still some concern of a clogged gas post when fermenting hoppier beers.

 

[bjhbrew]

@Dland thanks for the description of your process. I’ve thought of doing something similar but I’m intimidated by the need to monitor the gravity and intervene at a certain point. I’m curious, do you do a forced ferment in order to know the FG expected? I’d be worried transferring before final gravity that there would still be floaters that could clog the ball lock on the way out.

@501irishred let me know what you decide!

@ScrewyBrewer your concern for hop debris clogging is exactly why I’m hoping to do the entire ferment/carbonation in my primary (it pressure rated). Then I can cold crash before transferring

 

[Dland]

Don't be nervous, just do a trub dump and gravity reading when fermentation slows down. (assuming you have a conical like in your sketch) Not sure about your process or what you mean by floaters, none of them in my wort.

I'll go on to say some of you hoppers that clog up your gear with hops at certain stages, you could probably get similar or better results if you thought it though a bit more and,, no clogging problems.

 

[bjhbrew]

Aah, while my fermenter is in fact conical in shape, it does not actually have a dump valve so I would have to pop the top. Oh, or I could push a sample out of the floating diptube. Hmm. After you transfer to keg do you use a spunding valve or do you seal it up and trust that you have the right amount of remaining extract to carbonate correctly?

 

[Dland]

After you transfer to keg do you use a spunding valve or do you seal it up and trust that you have the right amount of remaining extract to carbonate correctly?

I give the kegs a little CO2 blast to assure keg lid is sealed. Then I just check them with the gauge on spunding valve once a day. That way I can monitor progress and judge when fermentation is complete. If pressure gets much above 30PSI, I let off some pressure.

However, if you do not have time or desire to check daily, there is nothing wrong with just setting your valve(s) to desired pressure and leaving them.

After a few batches it will all seem simple and routine.

 

[ScrewyBrewer]

@ScrewyBrewer your concern for hop debris clogging is exactly why I’m hoping to do the entire ferment/carbonation in my primary (it pressure rated). Then I can cold crash before transferring

If I understand correctly you’re favoring the option #2 setup then, correct?

Another question I have is, will the higher Co2 pressure in the fermenter hurt fermentation?

I like the idea of purging the kegs using the excess Co2. But my fermenters aren't rated high enough to support carbing beer in them. I like the idea though.

 

[bjhbrew]

Well so far I haven’t narrowed down my options; if anything it looks like I have more things to try out. As an update I went ahead and ordered the BlowTie spunding valve setup and it’s on its way on the slow boat from China. This is my first order from alie express and wasn’t my first choice but no one carries it in Canada and I only found two retailer in the us, one was out of stock and the other doesn’t ship to Canada. The BlowTie seems to be well regarded and hopefully removes the chance of leaking so I didn’t think I could go wrong. Once I get it I’ll go ahead and try it in each of the proposed arrangements.

 

[ScrewyBrewer]

I have a BlowTie valve inline on the gas line used when pressure transferring beer from the fermenter to a keg. Set to 3 psi it will vent off higher Co2 pressure spikes if they go above 3 psi.