Effectiveness of CO2 flushing small devices

[TheMadKing]

I just posted this question in the Norcal Yeast brink thread, but I thought it might warrant it's own thread

I'm looking at a NorCal yeast brink for dryhopping/injecting yeast starters into my new CF5 and most folks seem to be content with flushing the mason jar with CO2 a couple times and calling it "oxygen free." My process is big on removing O2 from the cold side as much as possible, and I have a hard time believing this is truly effective. This may be explored in depth in another thread, so forgive me if I'm just bring up something old and discussed to death, but I couldn't find it with several search terms.

Essentially what I'm asking is if a person follows this procedure or something similar:

"Attach the dry hop filled yeast brink to the conical but do not fully tighten the triclamp. Apply purge gas a few times and allow the purge to exit around the TC gasket. After purging a few times tighten triclamp and voila - O2 free dryhops"

How effective is it really?

Has anyone empirically measured to see if purging with CO2 like this ACTUALLY removes the oxygen? What pressure? How long? (I'm looking at you LODO guys, Bryan and Scotty)

I would appreciate some input from any of the scientifically minded among you - to my mind it would seem that the sudden influx of high pressure gas would make all kinds of crazy eddys that would effectively just make a mixture of air and CO2 unless you did it for a LONG time. I'm thinking of fluids as an analogy.

Fill a beer bottle with milk, then spray water into it and see how long it takes for it to be totally clear with no sign of milk. Maybe this is a bad analogy though.

I'm trying to think of a way to liquid purge it or something, in order to actually be sure the air is displaced. Or for some alternative solution:

• Boiled and quickly cooled water in a sealed mason jar with a TC valve on the lid, mix in your dry hops, and use a "capping device" that slides down inside the jar and floats on the liquid (like a mash cap would do in the mash tun) to create an adjustable physical barrier between the liquid and the headspace. So you put in your dry hops, push down the capping device to push the air out around the edges (think like a french press coffee maker), hook the jar up to your conical fermenter and apply enough CO2 pressure to the headspace to push the cap down and force the liquid up into your fermenter
• Mix up your hop and water solution with a tiny amount of sugar and use some yeast from your beer to scavenge oxygen before adding to your beer
• Make a TC compatible syringe-like device that holds dryhops and can be used to pull a slight vacuum that can be backfilled with CO2, then pushed out and repeated a couple times for good measure (seems more effective than just flushing alone)

 

[TheMadKing]

I wonder if something like this could be adapted to brewing - this seems like a great solution

https://www.researchgate.net/public...enting_air_from_degrading_jar-stored_products

 

[TheMadKing]

4-Pack of Fermentation Lids with Extractor Pump for Wide Mouth Mason Jar 4-Pack of Fermentation Lids with Extractor Pump for Wide Mouth Mason Jar:Amazon:Kitchen & Dining

This could also potentially be adapted to a 3" TC sight glass Yeast brink.

Hook it up to your dump valve, Suck out the air, backfill with CO2, repeat 5 times or so, and you might get closer to 0 O2.

Someone needs to come up with a MALE mason jar to 1.5" TC adapter... Or a jar with a lid at both ends (they exist but they are antiques and apparently worth $250 on eBay)

 

[kevink]

I attach a dry hop chamber to the top of my fermenter and fill it with dry hops. I then pull about 30" Hg vacuum on it and pressurize it with CO2 three times (vacuum, pressurize, vacuum, pressurize, vacuum, pressurize). I then open a sanitary valve between the fermenter and chamber and the hops drop in without even opening the chamber. There is zero exposure to O2. The valve is then closed and the chamber is removed.

 

[TheMadKing]

I attach a dry hop chamber to the top of my fermenter and fill it with dry hops. I then pull about 30" Hg vacuum on it and pressurize it with CO2 three times (vacuum, pressurize, vacuum, pressurize, vacuum, pressurize). I then open a sanitary valve between the fermenter and chamber and the hops drop in without even opening the chamber. There is zero exposure to O2. The valve is then closed and the chamber is removed.

View attachment 680332

Where did you get that chamber? And how are you pulling the vacuum?

Edit:

30"HG is atmospheric pressure.. I see what you did there

 

[kevink]

I made it out of readily available tri clamp parts. The vacuum pump is a two piston pump made by KNF. It pulls waaaay more vacuum than my Foodsaver.

 

[TheMadKing]

I made it out of readily available tri clamp parts. The vacuum pump is a two piston pump made by KNF. It pulls waaaay more vacuum than my Foodsaver.

Sorry I thought you were saying you used the atmospheric pressure as a 30" hg vacuum to purge your chamber.


If you're not intending that as a joke.. -30hg of vacuum is 100% vacuum. I work with industrial helium leak detectors sometimes that require a vacuum of 7 torr, and that takes large vacuum pumps that cost hundreds of $

You're not pulling a 100% vacuum on that thing. I guarantee it

 

[kevink]

No, not a joke. There are two ways to measure vacuum, right? 29.92" HG can mean perfect vacuum. And yeah, it pulls to between 29 and the 30" mark on my gauge. The pump was I believe $700, so I guess it really is possible? Like I said, waaay more vacuum than my Foodsaver can pull!

 

[TheMadKing]

No, not a joke. There are two ways to measure vacuum, right? 29.92" HG can mean perfect vacuum. And yeah, it pulls to between 29 and the 30" mark on my gauge. The pump was I believe $700, so I guess it really is possible?

Oh well yes if you spent $700 on it, you probably got a similar one to what I'm using, which is a NIST traceable lab grade vacuum pump

The different between 29"-30"hg is about 96% to 100% vacuum... In vacuum terms that's a HUGE difference. I have absolutely no problem believing you get to 96-97% vacuum with that pump.

 

[kevink]

10 torr/29.5" is what it's rated for, which is exactly what my gauge says.

 

[TheMadKing]

10 torr/29.5" is what it's rated for, which is exactly what my gauge says.

Yep that's about 97.something% vacuum.. Totally believable and sounds like a great method.. I'm not about to go rush out and spend that kind of money on a vacuum pump though.. Seems a bit steep

sorry about that initial reaction, I didn't mean to come off like a jerk, I just thought you were being a smarta$$

 

[kevink]

Lol, no worries. I was wondering why you were jumping on me for saying it pulls almost 30" HG, which it actually does. You can find them on ebay for a couple hundred.

 

[TheMadKing]

Maybe this subject really is a dead horse and I'm behind the times?

 

[kevink]

It has been discussed a lot. Have you seen this?

http://www.********************/wp-content/uploads/2018/01/ppm-O2-after-purge-chart-1.png

 

[TheMadKing]

It has been discussed a lot. Have you seen this?

http://www.********************/wp-content/uploads/2018/01/ppm-O2-after-purge-chart-1.png

Yes I'm very familiar with Doug's graphics, and that has been immensely helpful over the years. That refer to a purge cycle in a keg whereby you charge the space up to the pressure matched to the color, and repeat for the number of times shown on the x axis, and then release it back to atmospheric. I'm talking specifically about flushing an open container with continuous CO2 flow, so no pressure is built up inside the space before releasing. There are definitely some different mechanics in play

 

[Die_Beerery]

There is zero exposure to O2.

Except of course for the o2 impurities in the co2. But hey, that doesn't count right!
Zero o2 for everyone!

 

[TheMadKing]

Except of course for the o2 impurities in the co2. But hey, that doesn't count right!
Zero o2 for everyone!

Agreed.. It seems that nobody understands that gas is not pure ever, and the purity can be measured. You can certainly buy five-9 certified CO2 for lab grade applications but it's relatively expensive.

I don't know how many times I've been told by gas dealers "CO2 is CO2.. It's all the same"

I'm glad to see you on the forum Bryan, d you have any thoughts on my OP?.. OR is that something you might have measured at some point? You're probably the only person who just has the right equipment laying around lol

 

[Qhrumphf]

I know with my bulk CO2 supply at work, purging a tank bottoms out at about 8 ppb O2. That's presumably a combo of ingress in supply piping but mostly impurity of the gas itself.

 

[Qhrumphf]

Also, if you can somehow keep your vessel under positive pressure while open, it won't prevent O2 but it'll definitely help reduce it.

 

[TheMadKing]

I know with my bulk CO2 supply at work, purging a tank bottoms out at about 8 ppb O2. That's presumably a combo of ingress in supply piping but mostly impurity of the gas itself.

Thanks, and just to make sure I understand, you're talking about purging a large fermenter with continuous flow of CO2 and no pressure? Or are you pressurizingand releasing in purge cycles?

 

[Qhrumphf]

Yes, large vessel, though usually brite, not fermenter (though I'll do it with fermenters too when needed). I've done both ways. SOP at my current gig is tank blowing off at the top at 5 PSI with incoming CO2 through bottom carb stone at 20 PSI. That's verified by a DO meter at multiple tank locations. Previously done via 15 PSI cycles with no verification other than sniff test (but 4 cycles passed sniff test as well as current method).

 

[TheMadKing]

Yes, large vessel. I've done both ways. SOP at my current gig is tank blowing off at the top at 5 PSI with incoming CO2 through bottom carb stone at 20 PSI. That's verified by a DO meter at multiple tank locations. Previously done via 15 PSI cycles with no verification other than sniff test (but 4 cycles passed sniff test as well as current method).

How long do you have to keep the flow on at 20PSI to achieve 8ppb?

 

[Qhrumphf]

How long do you have to keep the flow on at 20PSI to achieve 8ppb?

Depends on the size. Bulk commercial tanks it's upwards of 4 hrs.

 

[TheMadKing]

Depends on the size. Bulk commercial tanks it's upwards of 4 hrs.

Holy crap.. That's a lot of CO2! Definitely not practical at the homebrew level

 

[Qhrumphf]

Holy crap.. That's a lot of CO2! Definitely not practical at the homebrew level

As I said, time goes up as vessel size goes up. A cornie keg or homebrew size unitank might take far less time. The important part is measuring the effectiveness. And *that* is not practical at homebrew level. The meter we use costs more than many cars.

 

[TheMadKing]

As I said, time goes up as vessel size goes up. A cornie keg or homebrew size unitank might take far less time. The important part is measuring the effectiveness. And *that* is not practical at homebrew level. The meter we use costs more than many cars.

Exactly why we are lucky to have people like you on the forum who can speak to this kind of thing

Thanks!

I'm thinking that I'll leave a dry hop charge in a chamber attached to a port on the top of the fermenter, from the start of Fermentation until dry hopping time. It'll need a cracked open butterfly valve on the bottom and a spunding valve on the top, and then the full volume of CO2 from fermentation can purge it. Then just fully open the valve when it's time to dryhop

 

[Qhrumphf]

Homebrew scale liquid purging a vessel is the ideal, as the only factor becomes incoming CO2 purity. If you're trying to purge dry hops, that's obviously not an option. A fermentation purged chamber on top is an elegant solution (that some pros use as well). I like to liquid purge a smaller chamber, keep it under positive pressure while adding hops to it, then cycle purge to satisfaction, then flow in with beer to partially liquid purge with beer, force back into tank through conical racking arm, and then cycle back and forth a few times. Even place a pump inline a recirculate with it which cuts your dry hop time way down. There are rigs specifically designed for this that'll self-purge with CO2, but they're even more expensive.

 

[TheMadKing]

Homebrew scale liquid purging a vessel is the ideal, as the only factor becomes incoming CO2 purity. If you're trying to purge dry hops, that's obviously not an option. A fermentation purged chamber on top is an elegant solution (that some pros use as well). I like to liquid purge a smaller chamber, keep it under positive pressure while adding hops to it, then cycle purge to satisfaction, then flow in with beer to partially liquid purge with beer, force back into tank through conical racking arm, and then cycle back and forth a few times. Even place a pump inline a recirculate with it which cuts your dry hop time way down. There are rigs specifically designed for this that'll self-purge with CO2, but they're even more expensive.

I may go your route as well with the multipurged container, because a major downside of the fermentation purged chamber is that it's a 1-shot deal, and I generally add 2 rounds of dryhops

 

[Qhrumphf]

The Sabco/White Labs FermFlask is great for both dry hops and anything else added post fermentation (like fruit or other adjuncts), but it's not cheap and is bigger than most homebrew batches (made from a HB sanke keg) so unless you're making BIG batches at home it's probably not useful.

 

[Qhrumphf]

(it also makes a fantastic yeast brink, which was the original purpose)

 

[TheMadKing]

The Sabco/White Labs FermFlask is great for both dry hops and anything else added post fermentation (like fruit or other adjuncts), but it's not cheap and is bigger than most homebrew batches (made from a HB sanke keg) so unless you're making BIG batches at home it's probably not useful.

Ha yeah I just looked it up, that's bigger than my average batch (I generally don't do more than 5 gallons unless I'm brewing for an event). I could probably buy some attachments for the NorCal yeast brink to do a similar procedure and then attach it under positive pressure.

Sounds like I'm going to need to buy a 20# CO2 tank too.. I'm sure glad my wife likes beer