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Common misconceptions about Vacu-vin (Don't use one for beer!)

Discussion in 'Beer Talk' started by domtronzero, Mar 7, 2013.

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  1. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    I posted this a while ago, and I don't think anybody ever put much thought into this, but I was hoping to help clear the air for future BAs (only those that'll actually read this though, I guess).

    Here's the link to the original post.

    I hope this sheds some light on the topic.

    In summation:
    1. A vacuum sealer WILL NOT pull CO2 out of solution (by means of Henry's Law).
    2. A vacuum sealer will still make your beer go flat due to the check-valve mechanical nature.
     
  2. ISO: sticky post button that'll keep this sucker at the top of the forum

    i mean, seriously, how many posts in a week are there about re-corking a bottle vs. using a vac sealer thingy ??
     
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  3. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Haha, thanks. I thought I did a pretty good job on it (shameless back-pat).

    But seriously, I'm so tired of rehashing this argument. And nobody ever seems to read my posts, or bother to acknowledge them.
     
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  4. Read. Acknowledged. Agreed.

    Thanks man!
     
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  5. tweezer159

    tweezer159 Savant (290) Alabama May 2, 2008

  6. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Ok, I guess I should clarify some semantics on the portion regarding that the Vacu-Vin will not pull CO2 out of suspension. It should have been explained as follows:

    Suppose one were to open a bottle of beer, thus allowing the built-up portion of CO2 to escape the headspace. Then it was vacu-vin'ed and recapped without a check-valve apparatus. A very minute portion of CO2 would have to escape solution in order to readjust the partial pressure of CO2 in the headspace (which is negligibly small in the first place) in order to achieve equilibrium of vapor pressure and the rest of the CO2 would remain in solution. The amount of CO2 that would be lost would be proportional to the amount of volume in the headspace.

    "A Vacu-Vin will remove a negligible (and in effect, unnoticable) amount of CO2 compared to using a simple stopper."
     
  7. I appreciate all of your posts. I also appreciate that you provided some clarification in your latest post (for accuracy reasons?).

    Isn’t the ‘bottom line’: “2. A vacuum sealer will still make your beer go flat due to the check-valve mechanical nature”?

    I mean if somebody is using a vacuum sealer to ‘preserve’ their beer it is counter-productive due to the check-valve mechanical nature?

    Cheers!
     
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  8. Duff27

    Duff27 Advocate (670) Illinois Feb 10, 2010

    Can we add this somewhere to the Beer 101 portion of the site?

    Once that happens we can refer people that post this to it...and make them feel shame.
     
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  9. Oh, for fuck's sake - JUST DRINK THE WHOLE BOTTLE!
     
  10. Has anyone experimented with canned air (CO2)? I'd be curious if spraying some "air" in the bottle before putting on the simple wine stopper would help at all.

    And thanks for posting!
     
  11. I agree just drink the damn thing! WTF
     
  12. If it was me I would be opening it and drinking it a half hour later anyway.
     
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  13. PJHealy

    PJHealy Aficionado (100) Ohio Jun 14, 2012

    Something I don't get: First you claim only a little bit of CO2 comes out of solution, because all that matters is the partial pressure of CO2. But then you claim that it keeps coming out of solution until the total pressure exceeds outside air pressure.

    So, why does it keep coming out of solution?

    (Not suggesting you're wrong. Just asking for clarification. I like your original post very much.)
     
  14. Nice info...I remember that debate on the old forums and have on a number of occasions thought about using that vin-vac thingy but then just said fudge it and drank the rest. But glad to see that it would be a waste of time anyway. If you're ever in SanDiego, find a guy named Mouli and tell him he owes you a beer. I'll make sure he knows about it;) Cheers.
     
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  15. Just buy 375's when drinking alone. or if your a lush glug the entire bottle!
     
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  16. What is the pressure that the valve opens at?
     
  17. I've had a seal last a long time. You just have to be careful and not shake it.
     
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  18. mudbug

    mudbug Advocate (535) Oregon Mar 27, 2009

    If you are wearing your pink panties and can't finish the bomber, put on your magic scientist glasses and do the following. Get a five gallon plastic bucket and a pound of dry ice. put the dry ice in the bucket and add about a cup of water, put that unfinishable bomber/growler in the bucket and wait a few minuets. When the fog of gaseous CO2 covers the top of the bottle give it a few seconds, slam the cork in. You have preserved the CO2 in the body of that half dead beer, you have removed the O2 from the headspace and you have forever relieved yourself from ever having to use the search function on BA. Let me know if it works, I always finish what I open, Cheers!
     
    rauchfest likes this.
  19. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Yes, it's the check-valve mechanism that is counter-productive to trying to keep carbonation in the beer. See my post below for more clarification.
     
  20. johnnyboy76

    johnnyboy76 Savant (370) Oregon Nov 20, 2010

    Not everybody wants to finish a 13.5% barleywine by themselves, especially at the end of the night after having 3 or 4 beers previously. Just sayin. But good for you if you want to. Drink up. But anyways as far as the vacuvin, I've seem to have had good luck with keeping carbonation if I pour the beer slowly and not create a big head in the bottle. Probably no science to it but, I've had beers last 4 and 5 days before and pour out with a good head and carb.
     
  21. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Ok, I guess I worded it in a kinda confusing way. For that I apologize.

    The CO2 will come out of suspension until the partial pressure of CO2 inside the bottle maintains an equilibrium at the vapor pressure for CO2 dissolved in water, at a specific temperature. If the bottle were left opened, seemingly all of the CO2 will be lost because there is barely any partial pressure of CO2 in the natural atmosphere.

    If a vacu-vin is used, it doesn't really change the partial pressure contribution of CO2 in the headspace because there isn't really any there in the first place. Therefore, it doesn't create a suction on the beer causing more CO2 to be lost. It isn't a function of overall pressure in the headspace, but only the partial pressure of the CO2 contribution in the headspace (which is very close to zero as it is).

    However, when a beer is opened (and especially when some beer is poured out, leaving a larger volume of headspace) it requires CO2 to come out of solution in order to maintain the required vapor pressure for equilibrium. CO2 will come out of solution and fill that space. And this is where the check-valve issue comes into play:

    I don't know exactly, but it really isn't too much. I've played with one and have blown air through it (holding it up to my mouth) and it wasn't difficult to get it to open up. Human lungs can really only exert about 2 psi of pressure (this was an experiment we did a long time ago in college where we blew into a U-tube filled with water and measured the height difference).

    With the average beer containing 2-3 volumes of CO2 dissolved in solution, there could be a pressure of at least 1 atmosphere above atmospheric. At serving temperature (38F) I have to keep my kegs at about 12-17 psi to achieve 2.5-3 volumes of CO2 in solution, with 30 psi required to maintain 4.5 volumes for my sours. This is a substantially large amount of pressure exerted in bottles. This is why most sours and Belgian beers are bottled in thick champagne-style bottles that can withstand that amount of pressure.

    Therefore, the pressure in your average bottle of beer is much more than enough to open the check-valve on the vacu-vin.

    So to further clarify another point:
    ...from a chemical standpoint. The check-valve nature will indeed make your beer go flat faster as shown in my previous post's illustration.


    Sorry for being so wordy. It was a long night at Societe ;)
     
  22. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    I live in San Diego. Where is this Mouli, and when can I collect? :)
     
  23. sukwonee

    sukwonee Advocate (560) Washington Dec 13, 2011

    Does this apply to Brauler?
     
  24. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    The Brauler's CO2 charging accessory pressurizes the growler with CO2, it doesn't create a vacuum. That's why the Brauler is awesome. If used correctly, it will maintain the right amount of carbonation in the beer. However, by opening the growler it introduces oxygen and can potentially oxidize the beer over time.
     
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  25. sukwonee

    sukwonee Advocate (560) Washington Dec 13, 2011

    thanks. I was on the fence about buying one (it's so damn expensive!!) and I will mostly get one now.
     
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  26. draheim

    draheim Poobah (1,050) Washington Sep 18, 2010

    This might be bordering on rocket science, but consider just saving that bottle for another night. I know your judgment is already impaired, but just take a moment to ask yourself whether you really need to open that bottle right now. A 13.5% barleywine isn't going to spoil if you don't get to it immediately.
     
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  27. willbm3

    willbm3 Savant (380) Massachusetts Feb 19, 2010

    Just finish your goddamn beer. And if you can't finish it don't open it.
     
  28. crytion

    crytion Savant (255) Ohio Jun 24, 2010

    NO. Don't just finish growlers that's ridiculous. this needs to be figured out. I just finished a growler of pliny that was shipped to me from California.I was pretty worried about losing carbonation. so I opened it and amazingly drank half of the growler with some friends. After that I slowly poured the rest into another 24 oz. pop top bottle leaving room for no air. meaning when I closed the lid beer spilled out. Then a week later I opened up the 24 oz. bottle and poured a beer (this is 2-3 weeks after its initial growler fill) and was delighted to see an inch of foam on that beer. I am sold on pop tops and will carry multiple sizes from now on every where that I go.
     
  29. What the Vacu-vin does , when the plunger is drawn up , is to increase the volume of the headspace which will of course reduce the pressure according to the general gas laws. This disturbs the equilibrium so that gas comes out of solution to restore matters as the pressure in solution must equal the pressure in the head space.Therefore its action does suck out some CO2.

    On a practical note I remember well that when my Dad reached his 90s his capacity for beer was sadly reduced and he used to make a bottle last for two or three days by the simple expedient of replacing the crown top.This didn't seal the beer as it was bent but it did keep the flies out! But carbonation was still acceptable the next day and oxidation was never present. But little if any oxygen gets into such a headspace anyway under these conditions.
     
  30. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Yah, replacing the crown cap is somewhat helpful. I always stick it back on an opened bottle, and it does help a bit.

    But I do have a problem with this:

    It doesn't increase the volume of headspace. That is determined by the physical dimensions of the bottle.

    But, in the end, it doesn't draw any more than a negligible amount of CO2 out of solution compared to the amount that is lost with a regular stopper. Ultimately, the amount of CO2 that is lost is a function of the amount of unpressurized (partial pressure of CO2) headspace left in the bottle when a bit of beer is poured out, which is a function of the amount of volume of airspace left in the bottle.

    The check-valve mechanism is a real issue though. See post #21 in this thread.
     
  31. The vacu-vin effectively becomes part of the head space when fitted and of course the action of raising the plunger increases it.When the plunger is returned , the valve closes and then the cycle is repeated on every stroke.
    All the CO2 in the bottle, whether in the headspace or in solution, is under the same pressure when equilibrium is achieved and basically whatever volume is pumped out by the vacu-vin will be promptly restored by more CO2 coming out of solution.Pumping the device removes gas-that's what it's for-so the more you pump the more CO2 is lost from the beer. Where else could it come from?
     
  32. Lare453

    Lare453 Champion (885) Florida Feb 1, 2012


    Can you say that?
     
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  33. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    I’m assuming that one opens a beer, pours a glass, then uses the vacu-vin and corks the bottle. Furthermore, once the beer is capped and put back into the fridge, the person does not return at a later time to pump it again.

    I'd like to quote some information from a message I received from emannths here just so I don't have to retype this. He and I went over this ad nauseum a few years ago (and I was arguing your stance):
    The dissolution of co2 from beer is not a fast reaction. In fact it is very, very slow when compared to many other reactions. The minute amount of time that the plunger increases the control volume is insignificant to the reaction. The driving factor is the reduction in pressure, and specifically the partial pressure of co2, in the headspace. The amount of co2 that comes out of the beer into the opened bottle during that short timeframe is very tiny. And since there is a tiny amount of co2 in the atmosphere already, there is a negligible reduction of partial pressure in the bottle when the pump is used. The co2 in the headspace is replenished rather slowly, and the amount and rate of dissolution of co2 will not be noticeable due to the use of a vacu-vin when compared to just leaving the cork off of the bottle.

    The gas that the pump is removing is primarily nitrogen and oxygen at first (atmospheric conditions). When the bulk of the gas is removed (actually only about half is removed because the vacu-vin reduces the pressure inside the bottle to about 1/2 atmosphere) it can only be replenished by CO2 from the beer. This reaction occurs quite slowly and reducing the pressure in the bottle does not accelerate this process, nor does it amplify it (Henry's Law).

    But the main issue with the device is the check-valve action of the stopper. See several posts above about how it doesn't work too well.
     
  34. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    Apparently I missed the joke or something.
     
  35. I love threads like this. I've learned a lot from this one. We are blessed with some very intelligent people across a wide range of industries on this site!
     
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  36. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    This thread has become tl:dr very quickly :)

    Edit: Marquis, I'm enjoying this discussion thoroughly. Thanks for giving me something to do on an otherwise slow day at the office. Cheers! :)
     
  37. rmalinowski4

    rmalinowski4 Savant (350) Illinois Oct 22, 2010

    So what if I purge the head space with CO2 from my kegging set up and then re-cap? That should keep the beer from being oxidized and keep the CO2 in solution, correct?
     
  38. domtronzero

    domtronzero Initiate (0) California Aug 18, 2007

    It would certainly help. Especially to prevent oxidation. But the molar mass of co2 at atmospheric pressure (from just squirting some co2 into the bottle) is about 1/2 to 1/3 lower than there is in the same volume at 15-30 psig (PV=nRT). This pressure is responsible for maintaining carbonation (and specifically the partial pressure of co2 only). So yah, you'd probably lose about a third less carbonation or so... if you were careful to completely flush the bottle with co2 and remove all other gases.
     
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