Author Topic: interesting question about purging with CO2  (Read 2046 times)

Offline Steve L

  • Brewer
  • ****
  • Posts: 483
  • Rocky Mount, VA
    • View Profile
interesting question about purging with CO2
« on: June 03, 2014, 08:16:22 PM »
So we're sitting around at work today, playing with dry ice that we receive as refrigerant for drug shipments and started thinking... When you drop it in water, the gas it emits is CO2. I've read a bit here and there about people using dry ice for various things in brewing. I wonder if you could use it to create a CO2 blanket in fermenters and bottling buckets and to purge bottles when bottling?

You could get a sports bottle with a flexible straw and attach a hose, and direct it into bottles, fermenters or buckets. I wonder if it would make enough of a difference and will it remain in the fermenter bottle or whatever long enough to make it effective. Any thoughts?
Corripe Cervisiam

Offline pete b

  • Official Poobah of No Life.
  • *
  • Posts: 3123
  • Barre, Ma
    • View Profile
Re: interesting question about purging with CO2
« Reply #1 on: June 03, 2014, 08:20:01 PM »
"If you melt dry ice, can you swim without getting wet?"
Steven Wright
Don't let the bastards cheer you up.

Offline Stevie

  • Official Poobah of No Life.
  • *
  • Posts: 6858
    • View Profile
Re: interesting question about purging with CO2
« Reply #2 on: June 03, 2014, 08:20:21 PM »
If you have access to free dry ice, sure. Otherwise, dry ice is pricey.

Offline Jimmy K

  • Official Poobah of No Life.
  • *
  • Posts: 3646
  • Delaware
    • View Profile
Re: interesting question about purging with CO2
« Reply #3 on: June 03, 2014, 08:23:30 PM »
It would work. You don't need water either, it just heats faster in water than air. I'm not sure it's a pragmatic answer though unless you have a free surplus of dry ice since it's expensive to buy. It might also be difficult to manage since you can't control the flow. You'd get a burst when you add a chunk, then it would fizzle quickly.
Delmarva United Homebrewers - President by inverse coup - former president ousted himself.
AHA Member since 2006
BJCP Certified: B0958

Offline mabrungard

  • Brewmaster General
  • *******
  • Posts: 2363
  • Water matters!
    • View Profile
    • Bru'n Water
Re: interesting question about purging with CO2
« Reply #4 on: June 03, 2014, 08:38:04 PM »
A recent thread on the probrewers forum points out that using nitrogen to purge vessels is much cheaper than CO2.

But who has a tank of nitrogen?
Martin B
Carmel, IN

BJCP National
Foam Blowers of Indiana (FBI)

Brewing Water Information at:
https://sites.google.com/site/brunwater/

Like Bru'n Water on Facebook
https://www.facebook.com/Brun-Water-464551136933908/?ref=bookmarks

Offline Slowbrew

  • Brewmaster General
  • *******
  • Posts: 2375
  • The Slowly Losing IT Brewery in Urbandale, IA
    • View Profile
Re: interesting question about purging with CO2
« Reply #5 on: June 03, 2014, 08:39:24 PM »
This is how a lot of rootbeer recipes handle carbonating the batch for an afternoon party.  Basically add water to round cooler, add extract, lower in block of dry ice and start adding sugar.  The bubbling mixes the sugar in and carbs the soda at the same time.  Once all the sugar is added, spin the top on until all the dry ice is thawed (very important step!!) and serve.

Like others have said it would be a very expensive way to carb your beverages if you couldn't get it for free.

Paul
Where the heck are we going?  And what's with this hand basket?

Offline Joe Sr.

  • Official Poobah of No Life.
  • *
  • Posts: 4345
  • Chicago - NORTH SIDE
    • View Profile
Re: interesting question about purging with CO2
« Reply #6 on: June 03, 2014, 08:55:07 PM »
A recent thread on the probrewers forum points out that using nitrogen to purge vessels is much cheaper than CO2.

But who has a tank of nitrogen?

Oddly, I do.  But it's a very small tank.
It's all in the reflexes. - Jack Burton

Offline Kinetic

  • Brewer
  • ****
  • Posts: 270
    • View Profile
Re: interesting question about purging with CO2
« Reply #7 on: June 03, 2014, 08:58:51 PM »
You exhale mostly CO2, so why not blow through a millipore filter and call it a day?

Offline braufessor

  • Brewer
  • ****
  • Posts: 330
    • View Profile
Re: interesting question about purging with CO2
« Reply #8 on: June 03, 2014, 09:11:55 PM »
You exhale mostly CO2, so why not blow through a millipore filter and call it a day?

Well, technically, you exhale mainly nitrogen....... but perhaps you could use this method for serving a stout or something ;)

Offline Kinetic

  • Brewer
  • ****
  • Posts: 270
    • View Profile
Re: interesting question about purging with CO2
« Reply #9 on: June 03, 2014, 09:35:18 PM »
Nitrogen is inert and would protect the beer as well as C02. 

Offline erockrph

  • Official Poobah of No Life.
  • *
  • Posts: 6185
  • Chepachet, RI
    • View Profile
    • The Hop WHisperer
Re: interesting question about purging with CO2
« Reply #10 on: June 03, 2014, 09:44:50 PM »
If you purge bottles with nitrogen rather than CO2, then you will lose CO2 from solution into the headspace after bottling. I'm not sure if it's enough to be a concern, but it's definitely something to do the math on before converting your brewery.
Eric B.

Finally got around to starting a homebrewing blog: The Hop Whisperer

Offline Stevie

  • Official Poobah of No Life.
  • *
  • Posts: 6858
    • View Profile
Re: interesting question about purging with CO2
« Reply #11 on: June 03, 2014, 09:47:54 PM »
Exhaled air still contains a significant amount of oxygen. Our lungs aren't perfectly efficient machines.

Offline HoosierBrew

  • Global Moderator
  • I must live here
  • *****
  • Posts: 13030
  • Indianapolis,IN
    • View Profile
Re: interesting question about purging with CO2
« Reply #12 on: June 03, 2014, 09:48:41 PM »
Exhaled air still contains a significant amount of oxygen. Our lungs aren't perfectly efficient machines.

Yep
Jon H.

Offline Stevie

  • Official Poobah of No Life.
  • *
  • Posts: 6858
    • View Profile
Re: interesting question about purging with CO2
« Reply #13 on: June 03, 2014, 09:52:01 PM »
Also, nitrogen is lighter than oxygen. Would that mean to purge, one would need to purge from the top. Co2 works because it is so heavy.

Nitrogen 14, oxygen 16, co2 44

Offline HoosierBrew

  • Global Moderator
  • I must live here
  • *****
  • Posts: 13030
  • Indianapolis,IN
    • View Profile
Re: interesting question about purging with CO2
« Reply #14 on: June 03, 2014, 10:06:41 PM »
If you purge bottles with nitrogen rather than CO2, then you will lose CO2 from solution into the headspace after bottling. I'm not sure if it's enough to be a concern, but it's definitely something to do the math on before converting your brewery.

Hadn't thought of that before, but it makes a lot of sense.
Jon H.