Using pressurized keg for closed transfer?

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Keith81

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Sorry if this has been asked and answered, I couldn't think up with a search phrase that came up with answers.

I am planning out my upgrade to kegging and would like to include closed transfers in that plan.

I ferment in a SS Brewtech Brew Bucket and use Norcal's CO2 Harvester (original version currently but considering the lid with ball lock and PRV).

My plan (hopefully this works) is to rig up a sanitized keg between the two jars to capture pure CO2 from fermentation to purge the keg. The first jar would catch any blow off and let the CO2 flow into the keg. Then air from the keg would be pushed out into the second jar which would act as an airlock. In this setup I'd have sanitizer in the second jar rather than having it start in the first and pushed to the second.

What I was then wondering was when I was ready to transfer could I hook up a line from the Brew Bucket to the Liquid Out on the keg and have the Gas In hooked to the first jar creating a closed loop. Would this setup allow beer to flow when opening the Brew Bucket valve, pushing the CO2 from the keg out into the jar and ultimately the fermenter or would it fail to drain similar to when you try to prime a pump with the tubing attached to the receiving vessel?

Thanks, Keith
 

JohnSand

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I'm not sure I follow, but I think I do.
I don't know if your ferment will produce enough CO2 to clear the keg. I'm pretty sure that if the flow from fermenter to keg is downhill, the keg will fill as long as the gas can escape.
 

mongoose33

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I think you're overcomplicating this. Just hook up a line from the fermenter to the OUT post of the keg, and open the PRV so the gas in the keg has someplace to go. You'll produce 20-25 volumes of CO2 which should clear the keg. Then when time to transfer from fermenter to keg, close the PRV, then hook up a line from the IN post to the normal out blowoff tube of the fermenter. As the beer racks into the keg, the CO2 it displaces will then flow back into the top of the fermenter, ensuring CO2 in the fermenter prevents air from coming in contact with the beer in the fermenter.

Here's how I've done it with mine:

This shows a line into the keg to purge it, and a line coming out of the keg to an airlock jar. It lets me monitor fermentation via the bubbling. All the blankets are covering the fermenter as part of crashing it.

purgingkeg.jpg

This shows purging a keg using the CO2 produced from fermentation. Using a jumper post I'm also purging the jumper I'll use to transfer the beer from the fermenter to the keg. This is one where the PRV is opened to vent the keg.


purgekegfermenterCO2.jpg


This pic shows sending the CO2 from the purged keg back to a fermenter as the beer is racked into it. There's nothing holy about using an airlock; it was all I had that fit the tubing I had. Now, I use a drilled stopper and a short piece of rigid plastic tube cut from a bottling wand.


o2freeracking2.jpg
 
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Keith81

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Nice setup @mongoose33! One question, since you go from blow off directly to keg what would you do in case of blow off? I suppose you'd just have to clean and sanitize the keg again and purge it using a different method?
 

mongoose33

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Nice setup @mongoose33! One question, since you go from blow off directly to keg what would you do in case of blow off? I suppose you'd just have to clean and sanitize the keg again and purge it using a different method?
I don't know--I've never had one. I've always had the sense that blowoffs are either due to not enough headspace, or fermenting too warm so the yeast takes off.

In the case of the conical fermenters, typically I do 5-gallon batches even though it's a 10-gallon fermenter. More than enough headspace to accommodate any nutso krausen. With the plastic fermenter I typically ferment at 64-66 degrees, controlled with a ferm chamber, so I don't get the crazy krausen.

YMMV.
 

brewbama

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With 5 gal of headspace I doubt you’d see any blowoff. I use a brew bucket which has about 1 - 1.5 gal headspace and have ended up with an inch of yeast in my airlock jar. That yeast and ‘barm’ would end up in a keg if I was setup like yours. There would have to be an intermediate jar between the fermenter and keg to catch the ‘stuff’.
 

4of7

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Sorry if this has been asked and answered, I couldn't think up with a search phrase that came up with answers.

I am planning out my upgrade to kegging and would like to include closed transfers in that plan.

I ferment in a SS Brewtech Brew Bucket and use Norcal's CO2 Harvester (original version currently but considering the lid with ball lock and PRV).

My plan (hopefully this works) is to rig up a sanitized keg between the two jars to capture pure CO2 from fermentation to purge the keg. The first jar would catch any blow off and let the CO2 flow into the keg. Then air from the keg would be pushed out into the second jar which would act as an airlock. In this setup I'd have sanitizer in the second jar rather than having it start in the first and pushed to the second.

What I was then wondering was when I was ready to transfer could I hook up a line from the Brew Bucket to the Liquid Out on the keg and have the Gas In hooked to the first jar creating a closed loop. Would this setup allow beer to flow when opening the Brew Bucket valve, pushing the CO2 from the keg out into the jar and ultimately the fermenter or would it fail to drain similar to when you try to prime a pump with the tubing attached to the receiving vessel?

Thanks, Keith
Primary keg pressure transfer
IMG_20180610_205251.jpg
 
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