How to: Balloon CO2 collection (Bruloonlock)

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DocAnna

Scottish Brewster
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I do worry about the amount of air and the oxygen it carries being drawn into my fermenter at cold crashing. I don’t have a CO2 cyclinder yet and am not at all sure about the investment in kegging and all the associated gas line paraphernalia. Having read about using mylar balloons to capture CO2 here on the forum and at Brulosophy 7 Methods For Reducing Cold-Side Oxidation When Brewing Beer

..… I thought oooh that looks a smart idea and I could do that instead. In all the guides I’ve read there isn’t any clear instruction on how to attach the tubing or pipe to the balloon and the ones so far I’ve seen have fixed connections to a bung or pipe, which is not ideal for storing while full of CO2. I also like things being neat and tidy, so after making three so far, here is my pictorial guide to making a BrüLoonLock. While not original, I tore two balloons before working out how to get through the valve, so hopefully this will be of some help.

The aim here is to form a reusable opening into the balloon that can bit connected on and off a piece of standard vinyl tubing. The challenge is getting through the mylar balloon valve without tearing the balloon. You will need: a hard plastic drinking straw (the reusable type) or similar hard tube, waterproof tape, electrical insulating tape, a hack saw, a piece of tubing, fine abrasive paper, some mylar balloons and part of an airlock.
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Start by locating the valve entry on the balloon and gently tease the drinking straw into between the layers, it will very quickly experience resistance from the valve as it enters the balloon.

To help open the valve, blow a little air through the straw into the balloon. Twisting can help but don’t grip the straw through the balloon as the valve is adhesive. Push the straw into the balloon and it will still be in the valve layers till it reaches the end again. This can be tricky but you need to feel the end of the straw through the layers of balloon and push the end of it through the thin plastic of the valve. This means gas can get into as well as out of the balloon.

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Trim the tail of the balloon close to the straw and fold back so that the edge can be wrapped around the straw. While the seal around the straw due to the adhesive is pretty good, its not enough, so use waterproof tape to form a seal between the folded over edges and straw.
Cut the straw in half and sand down the edge of the cut till smooth.

To make the reusable fitting to the tube, wrap about 6” of insulating tape around the straw and smooth down. Test the fit onto the tube, if the tape wrinkles up due to it being too tight, unwind a little and trim.
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For the other end of the tube cut off the bottom part of an old airlock (these are from bubblers that are too tall to use in my fermenting fridge), sand the cut smooth and push onto the end of the tube.
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The tube, balloon and fermenter can all be connected. The balloons once full can easily be disconnected, sealed with a small amount of tape and a new one added without disturbing the tube. This has the advantage of being able to collect the CO2 from an active fermenter to use for another one that is going to be cold crashed. All the parts are interchangeable so the tubing can be used for a blowoff valve and swapped to a balloon without disturbing the fermenter.

Hopefully useful.

Anna
 
I do worry about the amount of air and the oxygen it carries being drawn into my fermenter at cold crashing. I don’t have a CO2 cyclinder yet and am not at all sure about the investment in kegging and all the associated gas line paraphernalia. Having read about using mylar balloons to capture CO2 here on the forum and at Brulosophy 7 Methods For Reducing Cold-Side Oxidation When Brewing Beer

..… I thought oooh that looks a smart idea and I could do that instead. In all the guides I’ve read there isn’t any clear instruction on how to attach the tubing or pipe to the balloon and the ones so far I’ve seen have fixed connections to a bung or pipe, which is not ideal for storing while full of CO2. I also like things being neat and tidy, so after making three so far, here is my pictorial guide to making a BrüLoonLock. While not original, I tore two balloons before working out how to get through the valve, so hopefully this will be of some help.

The aim here is to form a reusable opening into the balloon that can bit connected on and off a piece of standard vinyl tubing. The challenge is getting through the mylar balloon valve without tearing the balloon. You will need: a hard plastic drinking straw (the reusable type) or similar hard tube, waterproof tape, electrical insulating tape, a hack saw, a piece of tubing, fine abrasive paper, some mylar balloons and part of an airlock.
View attachment 32741View attachment 32742

Start by locating the valve entry on the balloon and gently tease the drinking straw into between the layers, it will very quickly experience resistance from the valve as it enters the balloon.

To help open the valve, blow a little air through the straw into the balloon. Twisting can help but don’t grip the straw through the balloon as the valve is adhesive. Push the straw into the balloon and it will still be in the valve layers till it reaches the end again. This can be tricky but you need to feel the end of the straw through the layers of balloon and push the end of it through the thin plastic of the valve. This means gas can get into as well as out of the balloon.

View attachment 32743View attachment 32744View attachment 32745
Trim the tail of the balloon close to the straw and fold back so that the edge can be wrapped around the straw. While the seal around the straw due to the adhesive is pretty good, its not enough, so use waterproof tape to form a seal between the folded over edges and straw.
Cut the straw in half and sand down the edge of the cut till smooth.

To make the reusable fitting to the tube, wrap about 6” of insulating tape around the straw and smooth down. Test the fit onto the tube, if the tape wrinkles up due to it being too tight, unwind a little and trim.
View attachment 32746View attachment 32747View attachment 32748

For the other end of the tube cut off the bottom part of an old airlock (these are from bubblers that are too tall to use in my fermenting fridge), sand the cut smooth and push onto the end of the tube.
View attachment 32749

The tube, balloon and fermenter can all be connected. The balloons once full can easily be disconnected, sealed with a small amount of tape and a new one added without disturbing the tube. This has the advantage of being able to collect the CO2 from an active fermenter to use for another one that is going to be cold crashed. All the parts are interchangeable so the tubing can be used for a blowoff valve and swapped to a balloon without disturbing the fermenter.

Hopefully useful.

Anna

Marshall Schott would be proud. This is ace.
 
Out of interest, how much CO2 do you need during cold crash? I have a 33l bucket that I use to ferment 23l/5 gallon batch, so about 10l head space.
10 litres will be enough depends how cold you go in the cold crash, using the collection of vented CO2 and if you can ferment in a cube and collect the CO2 you can dispense straight from the cube keeping whatever you use to collect the gas. I have used a collapsible camping water carrier. Use whats left the same as a cask breather, you probably could use your bucket if the seal is good.
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Foil balloons are also an ideal way to serve beer at atmospheric, rather than top pressure. Details can be found on the thread ‘Draught Beer’, which I started in March 2019.
 
I do worry about the amount of air and the oxygen it carries being drawn into my fermenter at cold crashing. I don’t have a CO2 cyclinder yet and am not at all sure about the investment in kegging and all the associated gas line paraphernalia. Having read about using mylar balloons to capture CO2 here on the forum and at Brulosophy 7 Methods For Reducing Cold-Side Oxidation When Brewing Beer

..… I thought oooh that looks a smart idea and I could do that instead. In all the guides I’ve read there isn’t any clear instruction on how to attach the tubing or pipe to the balloon and the ones so far I’ve seen have fixed connections to a bung or pipe, which is not ideal for storing while full of CO2. I also like things being neat and tidy, so after making three so far, here is my pictorial guide to making a BrüLoonLock. While not original, I tore two balloons before working out how to get through the valve, so hopefully this will be of some help.

The aim here is to form a reusable opening into the balloon that can bit connected on and off a piece of standard vinyl tubing. The challenge is getting through the mylar balloon valve without tearing the balloon. You will need: a hard plastic drinking straw (the reusable type) or similar hard tube, waterproof tape, electrical insulating tape, a hack saw, a piece of tubing, fine abrasive paper, some mylar balloons and part of an airlock.
View attachment 32741View attachment 32742

Start by locating the valve entry on the balloon and gently tease the drinking straw into between the layers, it will very quickly experience resistance from the valve as it enters the balloon.

To help open the valve, blow a little air through the straw into the balloon. Twisting can help but don’t grip the straw through the balloon as the valve is adhesive. Push the straw into the balloon and it will still be in the valve layers till it reaches the end again. This can be tricky but you need to feel the end of the straw through the layers of balloon and push the end of it through the thin plastic of the valve. This means gas can get into as well as out of the balloon.

View attachment 32743View attachment 32744View attachment 32745
Trim the tail of the balloon close to the straw and fold back so that the edge can be wrapped around the straw. While the seal around the straw due to the adhesive is pretty good, its not enough, so use waterproof tape to form a seal between the folded over edges and straw.
Cut the straw in half and sand down the edge of the cut till smooth.

To make the reusable fitting to the tube, wrap about 6” of insulating tape around the straw and smooth down. Test the fit onto the tube, if the tape wrinkles up due to it being too tight, unwind a little and trim.
View attachment 32746View attachment 32747View attachment 32748

For the other end of the tube cut off the bottom part of an old airlock (these are from bubblers that are too tall to use in my fermenting fridge), sand the cut smooth and push onto the end of the tube.
View attachment 32749

The tube, balloon and fermenter can all be connected. The balloons once full can easily be disconnected, sealed with a small amount of tape and a new one added without disturbing the tube. This has the advantage of being able to collect the CO2 from an active fermenter to use for another one that is going to be cold crashed. All the parts are interchangeable so the tubing can be used for a blowoff valve and swapped to a balloon without disturbing the fermenter.

Hopefully useful.

Anna
Excellent write up and well detailed though in case of an active fermentation it would be better to place the balloon above the fermenter to prevent it getting krausen /beer gathering thus rendering the balloon only fit for single use.
 
Excellent write up and well detailed though in case of an active fermentation it would be better to place the balloon above the fermenter to prevent it getting krausen /beer gathering thus rendering the balloon only fit for single use.
Where ever it is situated when collecting the gas, a good idea is to put a receiver in between the vent and the collection. This will pick up the water and alcohol in the gas.
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For years I've used the hydration bladder for my CamelBak.
Super strong also, so I put it on my fermenter with a few points to go so it fills up with CO2 from the fermenter thus losing no aromatics.

Never sucked back the full amount of co2 in my bladder during soft and cold crashing

https://www.ebay.co.uk/itm/2-Litre-...792768&hash=item48b2f2e4fe:g:1dQAAOSwyN5fPUwg
Reminds me of these....

https://www.shop-optimum.com/en-gb/...G__VDFnQAzpzjgB46GZju8XcocutFG14aAnUUEALw_wcB
I used to work for a company that made them! ashock1
 
I've seen someone using night bags before. Quite surprised @DocAnna hadn't gone down that route! It's ingenious.
Thankfully we have lovely community nurses to deal with such things athumb.. so thankfully I rarely have to fiddle with catheter bags..... and I think second hand ones would be a bit euww even if thoroughly sanitised!

Anna
 
Thankfully we have lovely community nurses to deal with such things athumb.. so thankfully I rarely have to fiddle with catheter bags..... and I think second hand ones would be a bit euww even if thoroughly sanitised!

Anna

I would be absolutely happy to use a catheter bag for CO2 recapture! It's that perfect, you'd think it had been designed for that very purpose. I just wish I'd thought of it years ago before shelling out on a pressure fermentation vessel.
 
For those of you using corny kegs or better still @Buffers brewery king keg modification, instead of using a drinking straw use a length of John Guest 6mm tube.

Once you have that inserted you can then use the whole range of JG fittings to do whatever you want. I have the 6mm tube from the mylar balloon, connected to a 6mm tap so that I can disconnect easily. The 6mm tap then goes to a 6/8mm converter and the 8mm end connects to my spunding valve on the Fermzilla.

When using the collected CO2 to displace starsan in my king keg, it is then a simple matter of connecting the JG 6mm tap to a piece of 6mm tube, then into the 6/8mm converter and then 8mm tube on to a barbed disconnect. That goes on to my @Buffers brewery lid and it's all ready then for O2 free transfer of the brew from the Fermzilla.
 
I’m starting to think about CO2 harvesting and looking at my options. I’ve read about purging corny kegs of Starsan (or similar) using CO2 prior to filling with beer. What are your thoughts on purging keg with CO2 as above, but not immediately before filling but during fermentation meaning the keg could have a Starsan/CO2 mix for up to 2 weeks? Starsan will maintain sanitation (that doesn’t sound right) and CO2 will keep O2 at bay?
 
@Buffers brewery I have been thinking similar, but why not just get a 5 litre plastic container and fit a barbed pipe connector at the top and a barbed connector at the bottom, connect one with hose to your FV and one with hose to a blowoff bottle, this can be fitted at the start of fermentation if desired then will just work as normal but when cold crashing it cannot draw the water (or starsan) back into the FV but maintains a safe environment.
 
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