Clever priming sugar required

Fill one corny keg with sanitiser, use the ferment gas to purge the sanitiser out of one corny into the other and then purge that one as well.
You then have two kegs with no oxygen in.
Bringing another option into the room closed inject sugar mix ( half the amount for bottling carbonation ) and one gramme of Ascorbic acid into each keg.
Then closed transfer of beer into each keg.

Result two half filled kegs, no oxidation, building pressure from priming and only a need to supplement the volume of beer lost with equal CO2.

If you are trying to get rid of the CO2 cylinder you could fill one keg fully with the above method and then the other keg with some sugar, yeast nutrient and then use this ferment gas connected gas to gas periodically as your source of clean CO2.
Use an inline mini reg between the two kegs as your pressure control system or wing it using a simple connection and check with a pressure gauge.

Larse said:

And I've proven that calculator to be inaccurate. There should be a discussion on there between me and the site owner. For my calculation and actual result, it was out by over 100%.

For a 12psi 10 second pour, it gave me 0.9m of 4mm ID hose. I'm actually using 2.5m.

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I'd take it up with https://www.mikesoltys.com/

It's his PhD that calculator is based on.

You don't say what temperature your beer is at for your 12 psi.

But this thread might be a good starting point for your issues,

https://www.homebrewtalk.com/threads/critique-of-mike-soltys-hose-length-calculator.652483/

MashBag said:

I do now, from your links, know how to work out the required pressure. Then some smartass started on about oxidisation which lead to venting. So need more fermentation gas fot that too now.

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I don't believe you have a pressure fermenter.
I've used fermentation gas during pressurized fermentation to purge kegs filled with sanitizer.
Then do a closed transfer oxygen free.
Pressure fermentation is another rabbit hole to go down.

I do like a good rabbit hole

RoomWithABrew said:

I'd take it up with https://www.mikesoltys.com/

It's his PhD that calculator is based on.

You don't say what temperature your beer is at for your 12 psi.

But this thread might be a good starting point for your issues,

https://www.homebrewtalk.com/threads/critique-of-mike-soltys-hose-length-calculator.652483/

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Temperature doesn't matter if it's the same in both scenarios. But for the record it was 2°.

And the calculator is definitely wrong. I tested against it with two different hose IDs. There are other calculators out there that are closer to reality. The one on kegerators.com for instance.

Replacing all the beer lines on your kegerator isn't a fun task. I was spitting feathers when I had to do it a second time. I did it twice in a month because that calculator was wrong. So Mike Soltys can take his PhD and put it where the sun don't shine.

flush the headspace with CO2 before sealing ? (bottles only guy)

OK you guys have changed the plan.

Going to do 12+ bottles and one corny to 16/17l spunded to 30psi.

I don't agree the beer will spoil, but I do need something to compare it to, and why double the risk.

Additionally might have found another way.

MashBag said:

OK you guys have changed the plan.

Going to do 12+ bottles and one corny to 16/17l spunded to 30psi.

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Why 16/17l and not the capacity of the keg to below the gas dip tube?

I am trying to leave enough gas space in the corny for enough co2 to be made (by priming) to cover dispense.

I still think it is achievable

The easy solution to this, is double drop. Ferment for 16-24 hrs your primary fermenter, then transfer to the two corny kegs. No purging required as there's plenty of active fermentation to go, and trub will removed. Just fit each keg with a cheap blowtie spunding valve. Job done. Is was told by a pro brewer that if you transfer before you reach 50% then oxidation shouldn't be an issue.

https://www.northernbrewer.com/blog...rpz25aUJXeG0r6JcLfoM-XB2G6bAkgpBRfaqwd1TObmir

MashBag said:

I am trying to leave enough gas space in the corny for enough co2 to be made (by priming) to cover dispense.

I still think it is achievable

Click to expand...

There might be a minor problem with this? Not a problem unless you remove the CO2 cylinder, keep the yeast fed with sugar, don't care if the carbonation drops a bit. Sorry about a "classroom" post, but this should help keep the subject on-track ... may-be?

The beer will contain a saturation of CO2 from fermentation, as long as it's kept in an atmosphere of only CO2 at atmospheric pressure. Sounds complicated, but it's what we all do to keep air from contact with beer*. So, the beer has about 0.86 "volumes" of CO2 dissolved in it ... let's say 1 volume of CO2 to make it simple (this is important, because some of what follows is slightly wrong to keep this simplicity). Allow in 2x the headspace volume of CO2, there's already CO2 there so the cask now has x3 the headspace volume over the beer (about 29PSI[G!] ... and a coolish day of, say, 15C). The beer only has 1 volume dissolved in it, so it immediately starts dissolving more CO2 from the headspace. But the CO2 cylinder has a regulator, so as the CO2 dissolves the amount of CO2 in the headspace is topped up with more CO2. Eventually the headspace contains the original amount of CO2 (x3 the headspace volume) and the beer contains 3 volumes (x3 the volume of beer) of dissolved CO2 ... equilibrium!

Remove any beer with the CO2 disconnected, and the remaining beer will give up some of its CO2 to the headspace, so beer and headspace remain in equilibrium. I.E. The beer will have less than 3 "volumes". Use a different gas to CO2 to make up the pressure, and it will have no (zero, zilch ... etc) effect, except that the CO2 will disappear from the beer even faster (the beer wants to maintain equilibrium with the CO2 in the headspace, it doesn't give a fig for the new gas).

The beer's volume only changes minutely as more CO2 gas dissolves in it.

* Leave the beer in an unsealed bucket after fermentation is done and the CO2 will slowly (very slowly if the lid is a good fit) fritter away as air dissolves in the beer ... including oxygen! Note: The air does not "replace" the CO2, the air starts dissolving anyway, and the CO2 fritters away anyway. The amount of CO2 is (hopefully still less than!) 0.04% of air (400ppm). That is how much CO2 is left in the beer if nothing is done (constituents in air over beer, temperature and pressure all remain constant).

Peebee there is no co2 cylinder, that's the purpose of this proof of concept.

Sadfield said:

The easy solution to this, is double drop. Ferment for 16-24 hrs your primary fermenter, then transfer to the two corny kegs. No purging required as there's plenty of active fermentation to go, and trub will removed. Just fit each keg with a cheap blowtie spunding valve. Job done. Is was told by a pro brewer that if you transfer before you reach 50% then oxidation shouldn't be an issue.

https://www.northernbrewer.com/blog...rpz25aUJXeG0r6JcLfoM-XB2G6bAkgpBRfaqwd1TObmir

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Oo, that's sort of where I was going, but sooner. I was Day 6 ish krausen dropped, but still warm warm lively and has active yeast.

Thank you

MashBag said:

Oo, that's sort of where I was going, but sooner. I was Day 6 ish krausen dropped, but still warm warm lively and has active yeast.

Thank you

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How is day 6ish sooner than to 24hrs ?

MashBag said:

Peebee there is no co2 cylinder, that's the purpose of this proof of concept.

Click to expand...

Ahh ... you've changed goalposts or I've changed to another thread of yours? Never mind ... the info should be useful in trying to understand what you want to achieve.

Davegase said:

How is day 6ish sooner than to 24hrs ?

Click to expand...

He's saying it the other way round? "where I was going but sooner"

And where he's going is day 6.

peebee said:

There might be a minor problem with this? Not a problem unless you remove the CO2 cylinder, keep the yeast fed with sugar, don't care if the carbonation drops a bit.

Click to expand...

Or ... I think you've a problem!

peebee said:

Or ... I think you've a problem!

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I think the best way to deal with this potential problem is to give the keg a good shaking after it's filled, wait a bit and then purge. the shake will release some of the absorbed CO2 into the headspace and when that settles, the purge should remove any air. After that the yeast will get to work on the priming sugar and you're good to go.

I was tempted to offer a compromise but I don't think it would work for Mashbag.
To get to what he is aiming for. I would fill a clean keg and fill with a Starsan solution.
1st problem, I think Mashbag has a starsan phobia.
Then once I've had vigorous fermentation for a good 12 hours I would connect the fermenter gas out to the gas post on the keg and a blow off tube to the kegs liquid post to purge the keg fermentation gas.
2nd problem, Mashbag ferments in his brewing system.
Then once purged I would transfer the 17lt fermenting wort into the keg and the remainder into a demijohn.
Mashbag said he wanted to spund at 30psi. So attach a spunding valve and set to 30 PSI and let it go. No need to add priming sugar.
Once the fermentation has reached 30 PSI excess gas will be expelled.
This will result in ale carbonated to approximately 2.7 volume CO2 at a fermentation temperature of 20°C with the head space that he was aiming for.
It may also require a shortened or floating dip tube.