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Author Topic: Star San suck back  (Read 9843 times)

The Beerery

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Re: Star San suck back
« Reply #45 on: February 16, 2018, 03:23:36 pm »
Totally closed except for that 900ppm of o2 left in a sanipurged keg. Sorry I had to be that guy. On the bright side.. It's better then the other way!

Dude, I use your purging method.   Got a better one?

I know, its better! but its not perfect.  The fermentation purge is probably your best bet, but even there I still cringe at the thought of transferring finished beer.

The "pros" can put a sankey keg though the same cycles as a bottle with a dual/triple purge/vac. Then can discard the first runnings/keg and not flinch. We don't have those luxuries, we usually have one keg that we can't put though those cycles and 5/10 gallons specifically allotted.

Offline Robert

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Re: Star San suck back
« Reply #46 on: February 16, 2018, 04:03:17 pm »
Nor cal says they've run 30lbs into a Speidel, I wouldn't go more than 5. You'll see how they gallon out... I imagine 30 could make a pretty big bang if it fails

But 1 or 2 sounds smart.  I'll have to figure out what the negative pressure of cooling ~2gal by 30°F or so would be, you just need to counter that. After that, 5lb should be more than enough for a transfer.

EDIT  Tire guy says rule of thumb is 1psi/10°F

Didn't feel like dealing with gas laws myself, found a calculator from MIT to do it for me.  If inside of the fermenter is at atmispheric pressure at 64°F (my diacetyl rest) and I crash it, sealed, to 34°F, internal pressure will drop by 1.68psi.  So 1-2psi applied before crashing will yield negligible net effect.  (It looks like they develeoped this calc to work out change in a football taken from the coaches room to the field in response to deflategate!)
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Wilbur

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Re: Star San suck back
« Reply #47 on: February 16, 2018, 06:10:00 pm »
Nor cal says they've run 30lbs into a Speidel, I wouldn't go more than 5. You'll see how they gallon out... I imagine 30 could make a pretty big bang if it fails

But 1 or 2 sounds smart.  I'll have to figure out what the negative pressure of cooling ~2gal by 30°F or so would be, you just need to counter that. After that, 5lb should be more than enough for a transfer.

EDIT  Tire guy says rule of thumb is 1psi/10°F

Didn't feel like dealing with gas laws myself, found a calculator from MIT to do it for me.  If inside of the fermenter is at atmispheric pressure at 64°F (my diacetyl rest) and I crash it, sealed, to 34°F, internal pressure will drop by 1.68psi.  So 1-2psi applied before crashing will yield negligible net effect.  (It looks like they develeoped this calc to work out change in a football taken from the coaches room to the field in response to deflategate!)
That might be the best thing Brady has done for this country!

Bryan, remind me real quick where the 900 ppm is from? DO in the star San, the O2 contamination in the CO2, and where else? Can't remember if this is with an open transfer or not.

Offline MattyAHA

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Re: Star San suck back
« Reply #48 on: February 18, 2018, 12:59:44 pm »
As a side note I recommend making one of these the eliminate suck back.


 i made a DIY version, same design of this and i find it still pulls alot of air in..i used 2 half gallon jars and it pulled all the star san/co2 from one jar to the other, pushing the trapped co2 into the head space of the fermenter but it continued to pull air in as well which is just going to blend with the co2 in the headspace nullifying my attempt to keep o2 out.

« Last Edit: February 18, 2018, 01:02:09 pm by MattyAHA »
Matty


"This sweet nectar was my life blood"-  Phil "Landfill" krundle

Offline charlie

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Re: Star San suck back
« Reply #49 on: February 18, 2018, 08:03:45 pm »
I use 70% EtOH (diluted 95% Everclear) in my airlocks. 70% EtOH is the best strength to kill bacteria and yeast, and if it sucks back it doesn't matter.

I think that was recommended by Papazian in his "Complete Joy of Homebrewing".

Charlie
Yes officer, I know that I smell like beer. I'm not drinking it, I'm wearing it!

Offline Robert

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Re: Star San suck back
« Reply #50 on: February 18, 2018, 08:41:31 pm »
I use 70% EtOH (diluted 95% Everclear) in my airlocks. 70% EtOH is the best strength to kill bacteria and yeast, and if it sucks back it doesn't matter.

I think that was recommended by Papazian in his "Complete Joy of Homebrewing".

Charlie
Can't buy Everclear in many states, though.
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.

Offline Robert

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Re: Star San suck back
« Reply #51 on: February 26, 2018, 11:01:43 am »

I (fortunately) don’t have to deal with this issue, anymore. Anytime I cool my conical, I put on a lb or two of CO2.


Mylo


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Actually, that is a great idea, and I could do that on the Speidel.  Thanks for the idea.
In the end, I did away with the double jar thingy.   Just ran the tube from the gas QD on top of my Speidel into an open jar of Star San for fermentation,  and will use this idea and remove the QD and put on a couple of pounds pressure before crashing.
https://drive.google.com/file/d/1gzzQ9vDVWFMUIDdm8Mz1wd2HTlvNrmRI/view?usp=drivesdk
« Last Edit: February 26, 2018, 12:41:59 pm by Robert »
Rob Stein
Akron, Ohio

I'd rather have questions I can't answer than answers I can't question.