Spunding/Co2 process

[Cheesy_Goodness]

Sorry if this has been posted before, I did some research on this but wasn’t able to find anything with this exact set up.

I’ve been out of the fermentation game for quite some time now, hoping to get back in to it this summer. I got to thinking about pressure fermentation and how I could make it work with my setup but I’m not entirely sure this hypothetical process will work. Poke all the holes you can.

I’ve got a fermentation fridge that just barely can hold two corny kegs. Keg 1 and Keg 2 would both be there.

Keg 1 is my fermentation vessel with a floating dip tube; Keg 2 is serving vessel. Both have been sanitized beforehand.

Keg 1 ferments under pressure with a spunding valve attached at, let’s say 10 PSI. The output of the spunding valve goes to the input of Keg 2. Keg 2 has another spunding valve on it’s output.

My wort and yeast go in to Keg 1. I'll lightly pressurize it just to get it to seal and the beer ferments. My understanding is that since it’s under pressure I shouldn’t have to worry too much about blow off and can get pretty close to 5 full gallons in the keg. The excess pressure from Keg 1’s spunding valve goes in to Keg 2 and ultimately flushes it of all oxygen. I’ve seen posts around the internet that say fermentation produces enough Co2 to push starsan out of a keg so I’m assuming it’ll work the same without any liquid to push out. The spunding valve on the output of Keg 2 set to slightly less PSI than Keg 1, let’s say around 8-9 PSI.

When fermentation is complete I can do a closed transfer to the serving vessel by removing both spunding valves, and attaching a length of tubing on the output of Keg 1, and the other end to the output (filling from the bottom with a normal dip tube) of Keg 2. If the pressure in Keg 2 is less than Keg 1 my thought is it’ll slowly siphon the already carbonated beer into Keg 2. This will probably need dialed in a bit and may require hooking up my Co2 tank to Keg 1 to give it a boost, or tugging on Keg 2’s PRV every now and again.

If all goes according to plan, at the end of fermentation I’ll have:

• Carbonated beer (spunding valve)
• Clear beer, at least in theory (floating dip tube)
• Close to nothing spent on Co2
• Very little time spent on cleaning/racking (at least on the back end)

One sidenote: I realize I could potentially serve from Keg 1 with a floating dip tube and eliminate the need for Keg 2 and Keg 2’s spunding valve all-together. However I'd have to replace the dip tubes for 6-8 kegs and if my process is going to be as easy as I think it will be I won't really be spending much time racking. Could be totally wrong on that though, this whole post might just be making something simple far more complicated than it needs to be.

That’s about it. Like I mentioned I saw several variants on this plan but nothing exactly like this so I wanted to run it by you fine folks before I get the equipment this requires.
Thoughts?

 

[Jim R]

I would tweak a couple things. I would fill keg 2 with Star San and then push it out with the fermentation CO2 so there is never any oxygen in Keg 2.

To do a pressure transfer from Keg 1 to Keg 2, you will need to maintain a small pressure difference that won't quickly equalize as the beer shifts from one vessel to the next. I hook up my CO2 tank to my fermenting vessel to maintain this slightly higher pressure. By carefully controlling and minimizing this pressure difference between vessels, I also can prevent foaming as an issue. I also don't need 2 spunding valves to do what you are trying to do. When I do pressure transfers, I just use a small manual valve on the gas side of keg 2 that I open slightly till I see beer start to flow slowly from vessel 1 to vessel 2.

Otherwise this seems like what I do with my pressure capable fermenter (Fermzilla All Rounder) and my keg. The one advantage of this is that I know I have adequate head space in the fermenting vessel.

 

[Gnomebrewer]

I've tried versions of both (although not with spunding valves on both vessels), but ultimately found it easier to ferment in Keg 1 without pressure, liquid purge Keg 2 with bottled CO2 (only costs a few cents) and transfer to Keg 2 with a few gravity points remaining - spund in Keg 2. YMMV.

EDIT: and if your fermentation fridge only holds two cornies, using both for the ferment means you can have a full keg of beer into your serving keg.

 

[Cheesy_Goodness]

I would tweak a couple things. I would fill keg 2 with Star San and then push it out with the fermentation CO2 so there is never any oxygen in Keg 2.

To do a pressure transfer from Keg 1 to Keg 2, you will need to maintain a small pressure difference that won't quickly equalize as the beer shifts from one vessel to the next. I hook up my CO2 tank to my fermenting vessel to maintain this slightly higher pressure. By carefully controlling and minimizing this pressure difference between vessels, I also can prevent foaming as an issue. I also don't need 2 spunding valves to do what you are trying to do. When I do pressure transfers, I just use a small manual valve on the gas side of keg 2 that I open slightly till I see beer start to flow slowly from vessel 1 to vessel 2.

Otherwise this seems like what I do with my pressure capable fermenter (Fermzilla All Rounder) and my keg. The one advantage of this is that I know I have adequate head space in the fermenting vessel.

Hey Jim, thanks for replying.

I've seen the StarSan method before and would do it, but I've only got room for two cornies in my fermentation fridge so I wouldn't have a spot for the output. I do have a kegerator that I can use in a pinch but when the pipeline is built back up that won't be a real feasible option. It seems to me if I'm pushing most of the Co2 from fermentation into Keg 2 it should be full of enough Co2 and I wouldn't have to worry about oxygen. That may not be right though.
I guess an alternative would be to fill Keg 2 with StarSan then maybe add a few pounds of gas to it and let gravity suck it all out through the gas out post, I might be able to make that work.

I think I understand the basics of pressure transfer but I'm curious about the small manual valve you use on the gas side of keg 2 that you open. What does this get you if you already know the PSI of Keg 1 (because of the spunding valve) and Keg 2 (Co2 gauge)?

I am a bit concerned about headspace. I think pressure is going to help me out but I'll probably start out doing about 4 gallons and work my way up until I run into a problem.

 

[Cheesy_Goodness]

I've tried versions of both (although not with spunding valves on both vessels), but ultimately found it easier to ferment in Keg 1 without pressure, liquid purge Keg 2 with bottled CO2 (only costs a few cents) and transfer to Keg 2 with a few gravity points remaining - spund in Keg 2. YMMV.

EDIT: and if your fermentation fridge only holds two cornies, using both for the ferment means you can have a full keg of beer into your serving keg.

Hey Gnome,
Totally get where you're coming from, and I'm sure that works great.
One thing about that method that probably won't work for me though is timing the transfer to Keg 2 with a few points remaining. I hate it but I don't have the time to devote to the hobby like I used to. When I get a brew-day I'd rather do more work on the front end because who knows what my next week is going to look like between a kid, work, and other obligations.
I figure my method (if it's feasible) lets the beer ferment and finish out in Keg 1 for as long as I want and it'll still be pressurized. Then when it's time to keg I can transfer to an already purged keg.

 

[DuncB]

All good points, don't start flushing the other keg until ferment has been going a while so that all the oxygen in the keg is used up.

I don't bother starting flushing until krausen has started to drop, seems like lot of co2 is made when making beer.

One issue i see is that you have gas post and spund on keg 1
Gas out of spund1 into gas of keg 2
Spund on liquid post of keg 2 will get all of the starsan forced thru it. Not all spunding valves like that.

Instead Spund on keg1 gas post. Gas out to gas in on keg 2 ( filled with star san ) . Then liquid ball lock with open tube on it going to a bucket ( or your old ferment bucket etc) that can be outside the fridge. Once purged you'll still be pushing gas along so no oxygen gets back in.
Then go gas from 1 onto liquid of 2 no spunding valve. Put spund valve on the gas of keg 2.

You will need to crank the pressure up at this stage as you want carbed beer.

For example at 21 celsius and 2.3 vols you need 25psi.

So you will then have ferment keg and keg at 25 psi. Once keg pressured to this level you can disconnect and put spund back on gas post 1.

Cold crash ( pressure falls in ferment keg ) but it'll still be carbed to the right level. Then come transfer works better with height difference.

Remove spunding valve, Gas to gas ( this will balance the 25 psi across both kegs).

Then liquid to liquid ( remembering to flush that liquid line with co2 before starting ) . That can be done by brief purge from keg 2 as gas will come up the liquid line as it's just full of co2 before you start ).

Next check pressure in your keg and set the spund valve just below this pressure and put it on keg 2 gas post.
Siphon will then start.
Its a slow process and often aided by putting more CO2 into the ferment keg, I have a spare keg that I fill with CO2 during ferment to help this ( although I do have 3 CO2 cylinders ) I enjoy the challenge / eco offset.

Once transfer complete if the ferment keg has had boosted CO2 into it you can leave it gas to gas to help you serve the first few drinks before attaching the CO2 from cylinder.

Hope that helps.

I would add I use fermentasaurus so can see my krausen and haven't had problems with blowoff, this can be an issue with kegs i believe as they have less headspace.

 

[Jim R]

Hey Jim, thanks for replying.

I've seen the StarSan method before and would do it, but I've only got room for two cornies in my fermentation fridge so I wouldn't have a spot for the output. I do have a kegerator that I can use in a pinch but when the pipeline is built back up that won't be a real feasible option. It seems to me if I'm pushing most of the Co2 from fermentation into Keg 2 it should be full of enough Co2 and I wouldn't have to worry about oxygen. That may not be right though.
I guess an alternative would be to fill Keg 2 with StarSan then maybe add a few pounds of gas to it and let gravity suck it all out through the gas out post, I might be able to make that work.

I think I understand the basics of pressure transfer but I'm curious about the small manual valve you use on the gas side of keg 2 that you open. What does this get you if you already know the PSI of Keg 1 (because of the spunding valve) and Keg 2 (Co2 gauge)?

I am a bit concerned about headspace. I think pressure is going to help me out but I'll probably start out doing about 4 gallons and work my way up until I run into a problem.

I am not sure I understand about needing an output container in the fridge. It only takes a few minutes to push out Star San from a keg with a CO2 tank and only a little longer with fermentation CO2. I just run a small hose to a bucket to collect the Star San which doesn't need to be in the fridge.

Here is a video that shows the manual valve spunding-type valve that I made to use along with my main spunding valve. For transfers, I basically get equal pressure in both kegs (or in my case a pressure fermenter and a keg), connect a hose between the two and then use the manual valve on the gas side of the receiving keg to slightly release pressure in the receiving keg to start and maintain the transfer. I don't need a second spunding valve to do this when a cheap manual valve will work. Also, if I am not paying close attention when the receiving keg fills up, I don't want beer running through my expensive spunding valve. I would rather it go through this cheap manual valve which is easier to clean. Of course, once fermentation is complete, I need to apply a little CO2 to "keg1" to maintain the higher pressure to complete the transfer. It won't stay at 10-12 psi as I make the transfer.

 

[renstyle]

Do you have room next to your ferm-chamber for that serving keg to sit? I too have a 2-keg FC (barely), but I've opted to run the "blow off" line outside the chamber and do the purging there. I also utilize a "pressurized blow off bottle" with a 'tee' inside the FC as my first bubbler.

Here's my setup:
a. KEG 1 (ferm-keg) - gas post to a "primary blow off bottle" post with tube down into vodka
b. Ran another line off the gas-only side of the tee to outside of the fridge.
c. Connect spunding valve to this line outside the fridge.

This prevents vodka, trub, etc from gumming up the spunding valve.

Now you can connect a line to the OUTPUT of the Blowtie, and connect it to either:

Option #1 (starSan)
1) gas post of a starsan-filled keg
2) beer to beer jumper between sSan keg and the holding keg (what I use)
3) gas post of holding keg to a simple blow off bubbler I set on the counter to watch activity.

OR

Option #2 (empty serving keg)
1) output of Blowtie to BEER post on serving keg (should only have a slight amount of sanitizer inside, otherwise empty)
2) gas post of serving keg to blow off bubbler I set on the counter to watch activity

Option #2 will take some time to fully purge down the oxygen to acceptable levels via diffusion, but a 5 gal batch of beer produces well over 400 L<!> of CO2 gas, and running the majority of that thru even a non-purged serving keg will get the O2 levels down into the parts-per-billion range.

Note: If you are transferring from a ferm keg to a serving keg, tank CO2 will be needed. Only keeping it in a single vessel would obviate this need. You won't need to use any to PURGE the serving keg tho!

When it comes time to transfer your beer from ferm-to-serving keg:

1) move the spunding valve to the gas post of your serving keg.
2) beer to beer jumper between ferm and serving
3) use the CO2 tank to gently, slowly push the carbonated beer over to the serving keg

You'll need to watch it, and I'd suggest keeping the spunding valve higher than the kegs while doing this, to let gravity be your friend. There shouldn't be much fear of blasting beer thru the valve, but never hurts to be vigilant.

I've attached a pic of my FC to give you an idea of what this "pressurized blow off bottle" looks like. All-in was less than $10, including the Faygo where I got the bottle! LOL


EDIT: Now that I look at my FC, I suppose you could put an empty serving keg in there as well, and purge it the same as option #2 above, but with the tank in the chamber. You would just connect the spunding valve to the SIDE post of the 'tee' and it won't get mucked up even if the pressure fails and you do get a slight blow off (the bottle will hold it).

 

[DuncB]

@renstyle Good options. Just to say you can leave that T bottle empty and use it as a means of top harvesting blow off yeast, then swap out to your bubble system. I use a really small pet bottle for that and then can wash and top up the bottle cap it and I have yeast harvested no touch ( nearly ).

 

[Jako]

i can tell you what no to do.... don't link up two kegs and mix up the gas and beer post

 

[renstyle]

@renstyle Good options. Just to say you can leave that T bottle empty and use it as a means of top harvesting blow off yeast, then swap out to your bubble system. I use a really small pet bottle for that and then can wash and top up the bottle cap it and I have yeast harvested no touch ( nearly ).

I had not considered top harvesting. Nice!

 

[Cheesy_Goodness]

Do you have room next to your ferm-chamber for that serving keg to sit? I too have a 2-keg FC (barely), but I've opted to run the "blow off" line outside the chamber and do the purging there. I also utilize a "pressurized blow off bottle" with a 'tee' inside the FC as my first bubbler.

Here's my setup:
a. KEG 1 (ferm-keg) - gas post to a "primary blow off bottle" post with tube down into vodka
b. Ran another line off the gas-only side of the tee to outside of the fridge.
c. Connect spunding valve to this line outside the fridge.

This prevents vodka, trub, etc from gumming up the spunding valve.

Now you can connect a line to the OUTPUT of the Blowtie, and connect it to either:

Option #1 (starSan)
1) gas post of a starsan-filled keg
2) beer to beer jumper between sSan keg and the holding keg (what I use)
3) gas post of holding keg to a simple blow off bubbler I set on the counter to watch activity.

OR

Option #2 (empty serving keg)
1) output of Blowtie to BEER post on serving keg (should only have a slight amount of sanitizer inside, otherwise empty)
2) gas post of serving keg to blow off bubbler I set on the counter to watch activity

Option #2 will take some time to fully purge down the oxygen to acceptable levels via diffusion, but a 5 gal batch of beer produces well over 400 L<!> of CO2 gas, and running the majority of that thru even a non-purged serving keg will get the O2 levels down into the parts-per-billion range.

Note: If you are transferring from a ferm keg to a serving keg, tank CO2 will be needed. Only keeping it in a single vessel would obviate this need. You won't need to use any to PURGE the serving keg tho!

When it comes time to transfer your beer from ferm-to-serving keg:

1) move the spunding valve to the gas post of your serving keg.
2) beer to beer jumper between ferm and serving
3) use the CO2 tank to gently, slowly push the carbonated beer over to the serving keg

You'll need to watch it, and I'd suggest keeping the spunding valve higher than the kegs while doing this, to let gravity be your friend. There shouldn't be much fear of blasting beer thru the valve, but never hurts to be vigilant.

I've attached a pic of my FC to give you an idea of what this "pressurized blow off bottle" looks like. All-in was less than $10, including the Faygo where I got the bottle! LOL


EDIT: Now that I look at my FC, I suppose you could put an empty serving keg in there as well, and purge it the same as option #2 above, but with the tank in the chamber. You would just connect the spunding valve to the SIDE post of the 'tee' and it won't get mucked up even if the pressure fails and you do get a slight blow off (the bottle will hold it).

Option 2 sounds like more or less what I'm after, with the addition of the blow off bottle. I'll definitely keep this post saved when I'm putting it all together, thanks!

 

[Cheesy_Goodness]

@renstyle If you don't mind me asking, where did you pick up the T for your bottle setup?

 

[DuncB]

@Cheesy_Goodness
They are made by kegland, so available on aliexpress and should be available online in USA. Quite common in our LHBS.

 

[renstyle]

@renstyle If you don't mind me asking, where did you pick up the T for your bottle setup?

@Cheesy_Goodness
They are made by kegland, so available on aliexpress and should be available online in USA. Quite common in our LHBS.

I got mine from Williams Brewing:

https://www.williamsbrewing.com/Hom...ibution-Parts/Molded-Carbonation-Cleaning-Cap
https://www.williamsbrewing.com/Hom...istribution-Parts/Carbonation-Cap-Tee-Adapter
I wanna say these were cheaper when I purchased them, but now a pair of carb caps and a 'tee' are $15.00

Morebeer has them state-side also.

Going the slow-boat route with Alixexpress will be cheaper dollar-wise, but the shipping time will be extended. I purchased these in an order which gave me free shipping, so I didn't think it was too bad paying US-import prices.

 

[marc1]

Another option to consider:
Ferment in keg 1
Keg 2 empty
Keg 1 gas post to Keg 2 liquid post
Keg 2 gas post gets a spunding valve
Run your whole fermentation like this. Enough gas is produced to purge Keg 2.

 

[renstyle]

Another option to consider:
Ferment in keg 1
Keg 2 empty
Keg 1 gas post to Keg 2 liquid post
Keg 2 gas post gets a spunding valve
Run your whole fermentation like this. Enough gas is produced to purge Keg 2.

I used this <exact> setup for a few brews, and it does work.

My propensity for maximizing my beer output resulted in the keg filled pretty high, and even with several ferm-cap drops, when fermenting pressurized I always ended up with a bit of blow-off. This is why I now use the intermediate blow-off bottle, so none of the blow off makes it to the serving keg being purged.

Fermenting unpressurized most folks recommend 4.5 to 4.75 gal of liquid at most in the ferm-keg to give enuf headspace for the more vigorous yeasts.

When fermenting under pressure I admittedly shoot for more like 4.9/5.0gal volume, so while the blow-offs are entirely due to my choices, the bottle allowed me to keep doing this while still purging the serving keg and keeping things (relatively) clean.

 

[Jako]

Another option to consider:
Ferment in keg 1
Keg 2 empty
Keg 1 gas post to Keg 2 liquid post
Keg 2 gas post gets a spunding valve
Run your whole fermentation like this. Enough gas is produced to purge Keg 2.

just set mine up like this. so far its great. currently running my conical with a pressure transfer line on. 2PSI pressure relief on it. but i am just purging a keg so its working great.

 

[Jako]

I used this <exact> setup for a few brews, and it does work.

My propensity for maximizing my beer output resulted in the keg filled pretty high, and even with several ferm-cap drops, when fermenting pressurized I always ended up with a bit of blow-off. This is why I now use the intermediate blow-off bottle, so none of the blow off makes it to the serving keg being purged.

Fermenting unpressurized most folks recommend 4.5 to 4.75 gal of liquid at most in the ferm-keg to give enuf headspace for the more vigorous yeasts.

When fermenting under pressure I admittedly shoot for more like 4.9/5.0gal volume, so while the blow-offs are entirely due to my choices, the bottle allowed me to keep doing this while still purging the serving keg and keeping things (relatively) clean.

good to know. My newer kegs hold about 5.5G but i have some new to me old pin lock kegs (purchased from a online HBS) that hold 5G at most. also leak no matter what i do even new seals i am so over it.

Note to self. only buy used kegs from local venders.

 

[DuncB]

@Jako

Some of those atypical kegs need a different sized O ring, you might get some pointers on the forum from someone. I use Sankey kegs or key kegs so can't offer much advice.

 

[Jako]

@Jako

Some of those atypical kegs need a different sized O ring, you might get some pointers on the forum from someone. I use Sankey kegs or key kegs so can't offer much advice.

thanks for the advise. I might need to so some searching then. the lids are the issues. thought about buying new ones but that's just more cost i could have spent on new kegs.

 

[DuncB]

@Jako
I'd start a thread about that problem and I reckon you'll get the answer very quickly. Especially if you include some photos or a video. It's bound to be a well recognised problem. I started off reusing plastic disposable key kegs, bit of a hack but has served me really well as I didn't want to dive in spending 160 dollars a corney keg down here ( about 140 US ). They're quite expensive here! and seemed to have valves and things that could fail so I stayed away from them.

 

[Scottsj]

Another option to consider:
Ferment in keg 1
Keg 2 empty
Keg 1 gas post to Keg 2 liquid post
Keg 2 gas post gets a spunding valve
Run your whole fermentation like this. Enough gas is produced to purge Keg 2.

This is what I do as well but I swapped out the Corny for a 7.5 gallon Sanke so I can do full batches. Works awesome. Gravity transfers work as well if you get it flowing with remaining pressure in the ferm keg and then hook the two gas posts together to keep things balanced.

 

[DuncB]

@Scottsj
I don't find that the gravity and recirculate the gas seems to work very well, maybe it's the floating dip tube and small diameter tube on it and that it has to go up the tube before going down to the keg. Maybe not enough height? I tend to need to add some gas from another keg I previously overfilled.

 

[Scottsj]

@Scottsj
I don't find that the gravity and recirculate the gas seems to work very well, maybe it's the floating dip tube and small diameter tube on it and that it has to go up the tube before going down to the keg. Maybe not enough height? I tend to need to add some gas from another keg I previously overfilled.

I’ve had pretty good luck when using the floating dip tube as it does a good job of drawing clear beer. It’s definitely slower than a pressurized transfer but not terrible. I used to run into problems with trub when I used my brew bucket. Not sure if this has helped or not but I do blow some CO2 through the dip tube a day or two before transferring to clear any yeast or Krausen that may have settled in the tube. This also assures I have plenty of pressure to start the transfer if I didn’t spund. Any leaks in the line will stop the siphon of course so make sure your fittings are tight.

 

[DuncB]

@Scottsj
Not saying it doesn't work, just not as well as I hope. I tend to get my pickup tube flushed out when topping up the collection bottle on the fermentasaurus with beer after having dumped the yeast and hop stuff out.
It's really a factor of diameter, the floating dip tube is small, so is the keg post and the beer to beer line only 4mm internal diameter.
If the diameter was 25 % more across the board the flow would increase by 245%.
It just takes more patience than I can exercise.

 

[Jako]

@Jako
I'd start a thread about that problem and I reckon you'll get the answer very quickly. Especially if you include some photos or a video. It's bound to be a well recognised problem. I started off reusing plastic disposable key kegs, bit of a hack but has served me really well as I didn't want to dive in spending 160 dollars a corney keg down here ( about 140 US ). They're quite expensive here! and seemed to have valves and things that could fail so I stayed away from them.

prices are crazy, also corney kegs prices keep going up soon new ones will be the only way to go.

honestly i didn't know Disposable kegs were a thing. interesting. I have had a lot off issues in general with brewing gear. I had a Heating coil fail on me (burned 4 batches) my kegs leaking or missing dip tubes and my favorite lately was losing 5 Gallons of beer to the basement floor. I hope the dead bodies under the slab enjoyed it.... that's a joke no one take me seriously on that the house is new.

 

[DuncB]

@Jako
Key kegs, Uni kegs and several others. They are meant to be one way but I have reused several of them, they have a lifetime but the next new one is always just round the corner. They also make quite good low bar stools. I'm waiting to use one of them that had a barrel aged brett in it as the base and fermenter for a brett ipa, free pressure fermenter / server that can be chucked if problems.

 

[Cheesy_Goodness]

I figured I'd pop back in here with an update of what I ended up doing.

The kegs in the fridge have a floating dip tube. The "in" posts (CO2) from both kegs are joined by a nylon barbed T fitting, which leads to a plastic T carbonation cap (thanks @renstyle for that recommendation) attached to a 2L bottle. The out of the bottle goes to the out side of a keg (so it fills with gas from the bottom). The "in" side of that keg goes to another keg set up the same way. The "in" side of that keg is fitted with a Blowtie.

I've only done this once before with a lager strain fermented at ale temperatures. I remember filling the keg pretty full but didn't have any blowoff. Samples of the beer were pretty tasty, no off flavors detected. Fermentation was done in about a week.

This weekend was the first time using ale yeasts. I need to figure out a better way to manage blowoffs because right now it's looking like I'll need to re-sanitize the first empty keg. I didn't have the tubing suspended initially like the pictures below show but I think that might have helped if I had done that from the get go. I would have thought that the "blowoff bottle" would have filled up before going up the tube into the keg but that didn't seem to be the case.

Anyway, initial thoughts are that it's a neat system that I'll definitely stick with for lager strains, and if I can figure out a good way to better handle blowoffs I'll do it with ales too.

 

[marc1]

I figured I'd pop back in here with an update of what I ended up doing.

The kegs in the fridge have a floating dip tube. The "in" posts (CO2) from both kegs are joined by a nylon barbed T fitting, which leads to a plastic T carbonation cap (thanks @renstyle for that recommendation) attached to a 2L bottle. The out of the bottle goes to the out side of a keg (so it fills with gas from the bottom). The "in" side of that keg goes to another keg set up the same way. The "in" side of that keg is fitted with a Blowtie.

I've only done this once before with a lager strain fermented at ale temperatures. I remember filling the keg pretty full but didn't have any blowoff. Samples of the beer were pretty tasty, no off flavors detected. Fermentation was done in about a week.

This weekend was the first time using ale yeasts. I need to figure out a better way to manage blowoffs because right now it's looking like I'll need to re-sanitize the first empty keg. I didn't have the tubing suspended initially like the pictures below show but I think that might have helped if I had done that from the get go. I would have thought that the "blowoff bottle" would have filled up before going up the tube into the keg but that didn't seem to be the case.

Anyway, initial thoughts are that it's a neat system that I'll definitely stick with for lager strains, and if I can figure out a good way to better handle blowoffs I'll do it with ales too.

How much headspace did you have in the fermentation kegs? A little more space and some Fermcap might help with the blowoff issues.

 

[renstyle]

...
The kegs in the fridge have a floating dip tube. The "in" posts (CO2) from both kegs are joined by a nylon barbed T fitting, which leads to a plastic T carbonation cap (thanks @renstyle for that recommendation) attached to a 2L bottle. The out of the bottle goes to the out side of a keg (so it fills with gas from the bottom). The "in" side of that keg goes to another keg set up the same way. The "in" side of that keg is fitted with a Blowtie.

I've only done this once before with a lager strain fermented at ale temperatures. I remember filling the keg pretty full but didn't have any blowoff. Samples of the beer were pretty tasty, no off flavors detected. Fermentation was done in about a week.

This weekend was the first time using ale yeasts. I need to figure out a better way to manage blowoffs because right now it's looking like I'll need to re-sanitize the first empty keg. I didn't have the tubing suspended initially like the pictures below show but I think that might have helped if I had done that from the get go. I would have thought that the "blowoff bottle" would have filled up before going up the tube into the keg but that didn't seem to be the case.

Anyway, initial thoughts are that it's a neat system that I'll definitely stick with for lager strains, and if I can figure out a good way to better handle blowoffs I'll do it with ales too.

Nicely done. Had a question about your blowoff bottle setup... Do you have any tubing inside the 2L bottle connected to either of the carbonation caps?

When I run a bottle like this I have some 5mm-I.D. EVABarrier tubing (no clamps needed) running from the top-most carb cap to near the bottom of the bottle. The bottle is filled with enuf vodka to submerge the tubing near the bottom of the bottle, maybe an inch or 2. That way, in addition to catching any blowoff, it gives me fermentation feedback (bubbles).

The "side cap" is used to send the excess CO2 into the serving kegs.

In my setup, I do not harvest yeast from the blow off, so having vodka/StarSan/plain water in the bottle is OK for my needs.

I can see how leaving the bottle mostly empty will get you to the same place, just with no bubbling. I hadn't considered that previously, but it's a good idea.

 

[renstyle]

How much headspace did you have in the fermentation kegs? A little more space and some Fermcap might help with the blowoff issues.

Doing a pressure fermentation in a corny I get it pretty full, 18L (4.76gal). That leaves a bit over 2L of headspace in a standard corny keg. It's tight, but with Fermcap+pressure it really helps keep the krausen calm.

 

[Cheesy_Goodness]

How much headspace did you have in the fermentation kegs? A little more space and some Fermcap might help with the blowoff issues.

I didn't measure it but it was probably an inch or two below the CO2 dip tube. There wasn't much room. Never used Fermcap but it might be worth giving it a try. There wasn't much blowoff though all things considered. About half of what's in the bottle was Starsan. The stuff that made it in the tube past the blowoff bottle was probably a few ounces at most.

Nicely done. Had a question about your blowoff bottle setup... Do you have any tubing inside the 2L bottle connected to either of the carbonation caps?

When I run a bottle like this I have some 5mm-I.D. EVABarrier tubing (no clamps needed) running from the top-most carb cap to near the bottom of the bottle. The bottle is filled with enuf vodka to submerge the tubing near the bottom of the bottle, maybe an inch or 2. That way, in addition to catching any blowoff, it gives me fermentation feedback (bubbles).

The "side cap" is used to send the excess CO2 into the serving kegs.

In my setup, I do not harvest yeast from the blow off, so having vodka/StarSan/plain water in the bottle is OK for my needs.

I can see how leaving the bottle mostly empty will get you to the same place, just with no bubbling. I hadn't considered that previously, but it's a good idea.

Definitely should have used a piece of tubing on one of the caps! I'll do that next time, thanks for the tip(s)

I did notice this morning that if I have two beers connected to this set up like I show in the pictures, it is possible for blowoff from one keg to get into the other keg if one batch takes off faster than the other. I don't think it will really matter much since they're both actively fermenting but it is something to consider.

 

[Transamguy77]

@Cheesy_Goodness glad to see you back! I’m going to subscribe to this because this is what I want to do also. And when I finally get around to brewing again I’ll post back and let you know what I did and I’m sure you’ll do the same.

 

[DuncB]

Damm wrote this yesterday and forgot to press post.

I use the bottle for blowoff capture and depending on volume sometimes just attach the spunding valve to it. I don't put any liquid in it as a bubbler because you can harvest top crop yeast if you have a very sanitised bottle. Then swap it out later.
I don't tend to start flushing out and purging kegs until after the krausen has fallen, there's plenty of gas made after krausen. Just keeps it all a bit tidier.

Video only taken with bottle lying down for convenience of imaging, normally upright.

 

[tieflyer]

Ok, I have a 7 gallon fermonster plastic fermentor. I saw in a pic in post # 6 here where
DuncB maybe using a fermentasaurus pressure kit instead of a fermentation keg. I was wondering if i could use this kit with my fermonster?

 

[DuncB]

I'm not sure how much pressure a fermonster can take, but can't be much pressure to force the krausen out so could get into the collecting bottle.

 

[Elric]

I'm not sure how much pressure a fermonster can take, but can't be much pressure to force the krausen out so could get into the collecting bottle.

fwiw

I started to pop the base molding out at around 20psi on a one gallon fermonster. 5-10 psi can be easily held.