CO2 Woes. There's got to be an easier way!

[Sadfield]

All this talk of compressors, bladders and sugar solutions, doesn't really sound any easier than hooking up a tank of co2.

What about the issue of purity. The co2 from fermentation isn't pure, it contains many unwanted volatiles you don't really want to add back to a brew. Even without these impurities, how do you know when you've completely purged the fermenters headspace of oxygen, to a point you are collecting co2 only?

Just, trollin' y'all. Crack on.

 

[aolcot]

The co2 from fermentation isn't pure, it contains many unwanted volatiles you don't really want to add back to a brew. Even without these impurities, how do you know when you've completely purged the fermenters headspace of oxygen, to a point you are collecting co2 only?

This is exactly why I quickly stopped the practice of using the fermentation CO2 to purge a full keg of starsan to another.. In my effort to purge the keg of oxygen, I'm probably putting some oxygen back in + other volatiles depending on when I hook it all up during the fermentation..

 

[Agentgonzo]

This is exactly why I quickly stopped the practice of using the fermentation CO2 to purge a full keg of starsan to another.. In my effort to purge the keg of oxygen, I'm probably putting some oxygen back in + other volatiles depending on when I hook it all up during the fermentation..

This post goes into details on the CO2/o2 mix coming out of an airlock. It is heavy on the science/maths, but you can skim a lot of it.
In short, a typical fermentation produces roughly 400L of CO2. This is enough to purge 20 kegs. The later in fermentation you are, the less o2 coming out of the airlock.

At a very rough guess, I would say that after a full day of active fermentation, the O2 coming out of the airlock will be so small it won't affect your beer, and you'll still have plenty of active fermentation to purge your keg many times over.

 

[gyurmaember]

My chillies are more than happy to use the co2 from the fermentation. I still believe the easiest way to change supplier(I've deleted the second part of this sentence, because I try to be nice and polite).

 

[The Furnace Green Brewer]

Just got a beer engine and bottling

 

[Buffers brewery]

I came up with a complicated solution for delivering beer at atmospheric pressure without exposure to air that could be adapted to supply fermentation gas (for those like me that use it regularly for keg flushing with no adverse results) under pressure to dispense beer from a keg.

https://www.thehomebrewforum.co.uk/threads/hand-pull-pumps-and-balloons.94758/
The connector assembly would need to be modified (working on that) then the balloon could be filled with fermentation gas once inserted into the barrel and the space outside the balloon would vent to atmosphere through a second gas connector (where the radiator valve is). Then to dispense, the balloon connector becomes the (fermentation) gas out connector to the keg and the other connector can be used to pressurise the space to expel the fermentation gas. Simples

 

[Buffers brewery]

I came up with a complicated solution for delivering beer at atmospheric pressure without exposure to air that could be adapted to supply fermentation gas (for those like me that use it regularly for keg flushing with no adverse results) under pressure to dispense beer from a keg.

https://www.thehomebrewforum.co.uk/threads/hand-pull-pumps-and-balloons.94758/
The connector assembly would need to be modified (working on that) then the balloon could be filled with fermentation gas once inserted into the barrel and the space outside the balloon would vent to atmosphere through a second gas connector (where the radiator valve is). Then to dispense, the balloon connector becomes the (fermentation) gas out connector to the keg and the other connector can be used to pressurise the space to expel the fermentation gas. Simples

Prototype number 1. Test run tomorrow with air and water. Watch this space

 

[hoppyscotty]

I like key keg design, but they are one time use so not really feasible for home brewers. They work by you putting your carbonated beer in a bag within a keg, so you can carbonate during fermentation so no need to add any CO2. Then once in the bag you can pressurise the space between the keg and the bag with compressed air to whatever pressure you like as it doesn't change the carbonation level of the beer so you can have much more control over your serving pressure as you are breaking the link between serving pressure and beer carbonation level.

I've been racking my brain to suss out how you might modify a corny keg to be like a key keg. You can buy 20 litre bags which you could put inside the corny keg but then need a way to connect the bag valve to a corny lid so you can pull the beer out. Even if you use a new bag every batch it would be alot cheaper than a new key keg every batch.

 

[Branny]

10L refill is now £60 at Chorley. Massive increase over last 6 months.

 

[peebee]

I like key keg design, but they are one time use so not really feasible for home brewers. They work by you putting your carbonated beer in a bag within a keg, so you can carbonate during fermentation so no need to add any CO2. Then once in the bag you can pressurise the space between the keg and the bag with compressed air to whatever pressure you like as it doesn't change the carbonation level of the beer so you can have much more control over your serving pressure as you are breaking the link between serving pressure and beer carbonation level.

I've been racking my brain to suss out how you might modify a corny keg to be like a key keg. You can buy 20 litre bags which you could put inside the corny keg but then need a way to connect the bag valve to a corny lid so you can pull the beer out. Even if you use a new bag every batch it would be alot cheaper than a new key keg every batch.

@foxy is mucking about with these things. 10 litre Mini keg / Cask. They're not actually Key Keg (?) but very similar in design including the weird top so you can stack them. They come with Corny keg style posts. He's a bit cagey about them, probably while he assesses them first (great ideas are just that ... great ... but it's not so good telling everyone just before it turns out to be complete garbage!). Like newer Key Kegs, these are reusable designs.

I too have considered modifying a Corny keg. "Beer Out" shouldn't be a problem if you use flexible silicon tubing connected to a short ("gas in") dip tube and floating intakes on the other end inside the bag. Think it was Kegland doing this (always a happy hunting ground for different ideas). You would need a second tube connected to "Gas In", not for gas-in but for venting gas out should the bag start to over pressure. You'd also need a third port for pressurising about the outside of the bag (a bike pump for "cask conditioned" and hand-pumped beer, a compressed air cylinder for higher pressure). Fill the bag by pumping into the "beer out" post (or the "gas in", there can be no splashing if the bags are completely evacuated first) ... this is how I fill Corny kegs now (using food-safe diaphragm pumps that don't whip the beer into a froth).

Cor, putting it in writing makes me dream of starting another project!

What bags have you sourced?

 

[Sadfield]

Why not approach it the other way @peebee. A corny operates in top pressure, so putting something such as a bag or balloon on the gas in would do the same job, but provide a barrier between the beer and whatever gas you pressurised with.

As for bags, these would be strong enough.

Https://www.balliihoo.co.uk/replace...MAvpfr-nP7Vd1upYzhgdiCcSQCglHZ_MaAgcKEALw_wcB

 

[Leon103]

I pay £24 for a new bottle. Just shop around

 

[peebee]

Why not approach it the other way @peebee. A corny operates in top pressure, so putting something such as a bag or balloon on the gas in would do the same job, but provide a barrier between the beer and whatever gas you pressurised with. ...

I'll admit I hadn't been thinking off it that way around. Pros and Cons. It has got to be simpler to set up with the bag in the beer rather than around it, but that way around increases the cleaning tasks rather than decreasing them and it misses out on avoiding the need to purge the airspace with CO2 (there is probably no such "need" but it has become a bit of a habit to stress over if not done).

It's something for me think more about.

I pay £24 for a new bottle. Just shop around

I pay much less than that (though I haven't checked on price for a year or two); it's just not the point. Being slaved to CO2 supplies when what I brew hardly needs any ("cask conditioned", very low carbonation, CO2 only provides a safe way of dispensing). Others have their reasons, not least being some can try as hard as they like, but unless willing to drive 100 miles or more can't find cheap gas.

Anyway: "Shop around"? In Wales! I can forget that.

 

[Leon103]

I'll admit I hadn't been thinking off it that way around. Pros and Cons. It has got to be simpler to set up with the bag in the beer rather than around it, but that way around increases the cleaning tasks rather than decreasing them and it misses out on avoiding the need to purge the airspace with CO2 (there is probably no such "need" but it has become a bit of a habit to stress over if not done).
It's something for me think more about.
I pay much less than that (though I haven't checked on price for a year or two); it's just not the point. Being slaved to CO2 supplies when what I brew hardly needs any ("cask conditioned", very low carbonation, CO2 only provides a safe way of dispensing). Others have their reasons, not least being some can try as hard as they like, but unless willing to drive 100 miles or more can't find cheap gas.
Anyway: "Shop around"? In Wales! I can forget that.

Wasn't talking to you. Was answering the OP

 

[Buffers brewery]

As CO2 is by-product of the brewing process I was wondering if anyone had managed to successfully use pressured kegs or CO2 capture and compression?

What, this question?

 

[RoomWithABrew]

I think this post clears up a lot of the questions or myths people have about using ferment gas. Bit technical but not hearsay or I think so.
https://www.homebrewtalk.com/showpost.php?p=8004741&postcount=3

 

[hoppyscotty]

@foxy is mucking about with these things. 10 litre Mini keg / Cask. They're not actually Key Keg (?) but very similar in design including the weird top so you can stack them. They come with Corny keg style posts. He's a bit cagey about them, probably while he assesses them first (great ideas are just that ... great ... but it's not so good telling everyone just before it turns out to be complete garbage!). Like newer Key Kegs, these are reusable designs.

I too have considered modifying a Corny keg. "Beer Out" shouldn't be a problem if you use flexible silicon tubing connected to a short ("gas in") dip tube and floating intakes on the other end inside the bag. Think it was Kegland doing this (always a happy hunting ground for different ideas). You would need a second tube connected to "Gas In", not for gas-in but for venting gas out should the bag start to over pressure. You'd also need a third port for pressurising about the outside of the bag (a bike pump for "cask conditioned" and hand-pumped beer, a compressed air cylinder for higher pressure). Fill the bag by pumping into the "beer out" post (or the "gas in", there can be no splashing if the bags are completely evacuated first) ... this is how I fill Corny kegs now (using food-safe diaphragm pumps that don't whip the beer into a froth).

Cor, putting it in writing makes me dream of starting another project!

What bags have you sourced?

I've not sourced any bags as yet, just done a quick google search and seen them...think they are the bags that go inside a box as part of a 'beer in a box' thing. On the basis you fill key kegs upside down I just wondered if you could just put the bag inside a corny keg upside down, connect a flexible hose to the liquid post then that's job jobbed. you'd fill the bag with ready carbonated beer via the liquid post with the PRV open. Once filled you could hook up the gas post to the compressed air. I can't see in principle why this wouldn't work as long as there was nothing protruding that would puncture the bag. Not sure how tough these beer bags are.

The compressed air source could be a small diving cylinder. Not sure what regulator you could use. OR maybe even hook up a pump action garden sprayer to the keg. Would require more elbow work to maintain sufficient pressure to push the beer out.

 

[RoomWithABrew]

I've not sourced any bags as yet, just done a quick google search and seen them...think they are the bags that go inside a box as part of a 'beer in a box' thing. On the basis you fill key kegs upside down I just wondered if you could just put the bag inside a corny keg upside down, connect a flexible hose to the liquid post then that's job jobbed. you'd fill the bag with ready carbonated beer via the liquid post with the PRV open. Once filled you could hook up the gas post to the compressed air. I can't see in principle why this wouldn't work as long as there was nothing protruding that would puncture the bag. Not sure how tough these beer bags are.

The compressed air source could be a small diving cylinder. Not sure what regulator you could use. OR maybe even hook up a pump action garden sprayer to the keg. Would require more elbow work to maintain sufficient pressure to push the beer out.

Beer bag would need to be oxygen impermeable. Otherwise beer will oxidise in the bag.

 

[Buffers brewery]

View attachment 75784
Prototype number 1. Test run tomorrow with air and water. Watch this space

So, after making a few plumbing changes and chasing a couple of leaks down, I managed to fill the internal mylar balloon with air while venting the barrel space. Connecting the balloon to a King Keg full (5 gallons) of water I was able to pressurise the barrel up to 7 psi and consequently pressurised the King Keg up to 6 psi (gauges were not calibrated to each other) and water was dispensed from the King Keg beer out line. Managed to dispense over half of the King Keg. Next step (in a couple of weeks) is to see if I can fill the internal mylar balloon with fermentation gas from the fermentation bucket with actual beer being fermented . Watch this space.

 

[hoppyscotty]

Beer bag would need to be oxygen impermeable. Otherwise beer will oxidise in the bag.

True, but would like to think a bag intended for storing beer would be impermeable to O2...but worth checking out.