Brainstorming about ways of recapturing CO2 from fermentation

[Agentgonzo]

I save some of my fermentation C02 into used and sanitised 20l polypin ale bags, they quickly blow up at the beginning.

I have thought about collecting gas into a polypin like you've done, then putting it into some kind of press to increase the pressure with some reinforcement to prevent the plastic having to do all the work of holding the pressure in, but did'nt really get anywhere. I presume that if it was easy, there would be guides all over the internet on how to do it.

 

[TNP]

Well I said bags because I have bags and not balloons at home right now, wouldn't mind to use balloons if it works

 

[TNP]

I save some of my fermentation C02 into used and sanitised 20l polypin ale bags, they quickly blow up at the beginning.
View attachment 86487

These are connected to the gas post of a keg which I serve through a hand pull similar to cask but protecting the beer, although it tends not to spend to much time in the keg once opened.
View attachment 86488
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Any problems with fermentation byproducts?

 

[Agentgonzo]

Well I said bags because I have bags and not balloons at home right now, wouldn't mind to use balloons if it works

the end result will be the same. You won't get much more than what you get just by fermenting at room pressure. In order to increase the pressure enough to notice, you'll need something more than a thin bag/balloon.

 

[Caramel Ox]

Well you could carbonate the beer by spunding a pressure fermenter at the end of fermentation. And then do what with it though? Serve with a hand pull?

 

[Chippy_Tea]

mmmm, that lovely latexy taste in your beer.

You could try the flavoured ones

 

[Agentgonzo]

Well you could carbonate the beer by spunding a pressure fermenter at the end of fermentation. And then do what with it though? Serve with a hand pull?

You'd need a fermenter that can hold the pressure, but this does seem to be the best option for people wanting to carbonate with fermentation gas.
IIRC my SS fermenter (BrewDevil, but the same as Klarstein, SS Brewtech etc) can hold maybe 4 extra bar (about a quarter of an atmosphere). Plastic buckets won't hold any.

 

[Leon103]

You could try the flavoured ones

Or he could try food grade co2

 

[Clarence]

Just get some bottles and caps and have done with it.

 

[CaptAwol]

I have thought about collecting gas into a polypin like you've done, then putting it into some kind of press to increase the pressure with some reinforcement to prevent the plastic having to do all the work of holding the pressure in, but did'nt really get anywhere. I presume that if it was easy, there would be guides all over the internet on how to do it.

The gas in the bag is only to fill the void as beer is pulled off, no intention to carb or pressure

 

[Buffers brewery]

Just for a laugh I thought I’d share this link to one of my old posts. Mylar balloons are the preferred collector of fermentation gas as it’s less gas permeable (CO2 can’t seep through the balloon wall and O2 can’t enter, this can and does happen with different plastic materials). Theoretically, the pressurised fermentation gas “could” carbonate cold beer, but how many “barrelsworth” of gas you’d need, I have no idea.

https://www.thehomebrewforum.co.uk/threads/pressurised-fermentation-gas-anyone.100537/

 

[CaptAwol]

Any problems with fermentation byproducts?

I'm not sure what you mean or concern is about byproducts, as I serve from a keg via a hand pull I consider 2 options;
1. Use bottle C02 in which
a. Attach C02 and apply minimum pressure to replace void
b. Attach C02 and apply pressure for carb

2. Not use bottle C02
a. Open gas post and air is drawn into void
b. Attach C02 bag so C02 is drawn into void

I opt for 2b as I prefer low carb beer and it keeps much better and longer without air reducing the quality and life of a keg.

 

[TNP]

I'm not sure what you mean or concern is about byproducts, as I serve from a keg via a hand pull I consider 2 options;
1. Use bottle C02 in which
a. Attach C02 and apply minimum pressure to replace void
b. Attach C02 and apply pressure for carb

2. Not use bottle C02
a. Open gas post and air is drawn into void
b. Attach C02 bag so C02 is drawn into void

I opt for 2b as I prefer low carb beer and it keeps much better and longer without air reducing the quality and life of a keg.

Byproducts as in the nasty stuff that fermention "farts" out with CO2, as written in previous posts.

I'd opt for 2b too, in fact I think I will

 

[CaptAwol]

Byproducts as in the nasty stuff that fermention "farts" out with CO2, as written in previous posts.

I'd opt for 2b too, in fact I think I will

Too much scare mongering goes on with homebrewer's.
For the time it takes me to demolish a keg I probably don't need to worry about oxygen getting drawn in, however I'm a hophead but I prefer session beers.
Whilst strong hoppy beers do retain hop flavours, session beers deteriorate quickly especially cask served, so perhaps in answer to your previous reply, with my setup I think I retain a lot of hop aroma and flavour.
Disclaimer; my beers don't spend long in kegs anyway

 

[Justin Dean]

When pressure brewing co2 carbonates as it ferments. Are we concluding it is bad carbonation because the co2 under pressure from the ferment is bad?

 

[Sadfield]

Too much scare mongering goes on with homebrewer's.

It isn't scaremongering. It's asking why you'd want to add back the volatiles you've spent time and care to remove, by reusing co2 for carbonation.

When pressure brewing co2 carbonates as it ferments. Are we concluding it is bad carbonation because the co2 under pressure from the ferment is bad?

The CO2 is neither good or bad. As it leaves the fermenting wort it carries other things with it, in the same way steam from the boil does. Pressure fermentation just restricts the rate of venting, it isn't a completely closed system.

 

[Leon103]

It isn't scaremongering. It's asking why you'd want to add back the volatiles you've spent time and care to remove, by reusing co2 for carbonation.

The CO2 is neither good or bad. As it leaves the fermenting wort it carries other things with it, in the same way steam from the boil does. Pressure fermentation just restricts the rate of venting, it isn't a completely closed system.

And why you don't seal it during the first few days

 

[dtashmore]

I have been pressure fermenting for more than a year, at the end of the ferment I have fully gassed ale, no off flavors as the pressure inhibits the yeast from creating them. it also helps me make good ales in the South African summer temperatures of over 30 degrees. it saves me bottled CO2 and assists with both kegging and bottling. the down side is that it eliminates nearly all of the yeast esters which would affect the final result of many ester prominent ales, good for lager though as it replaces the need for lagering.

 

[Justin Dean]

I have been pressure fermenting for more than a year, at the end of the ferment I have fully gassed ale, no off flavors as the pressure inhibits the yeast from creating them. it also helps me make good ales in the South African summer temperatures of over 30 degrees. it saves me bottled CO2 and assists with both kegging and bottling. the down side is that it eliminates nearly all of the yeast esters which would affect the final result of many ester prominent ales, good for lager though as it replaces the need for lagering.

Exactly

 

[Sadfield]

....nothing to do with harvesting CO2 and using to carbonate fermented beer.