Sunday, June 01, 2014

To squeeze, or not to squeeze, that is the question

There’s this ongoing and maybe not-so-silent argument happening at my house. 

Bottles.  I’m talking 2 liter soda bottles here folks, and the age old argument of whether squeezing a soda bottle (or not) makes the soda stay fizzy longer.  Hubby’s a squeezer and I’m most definitely not.  In fact, the actual squeezing of the soda bottle ticks me right off.  (I get mad about stupid things.  Yes, I know this.  Don’t judge.)  Aside from the fact that it’s just not aesthetically pleasing, which offends my delicate sensibilities, it makes the bottles unwieldy.  And on top of that, I just think he’s wrong.  He claims that squeezing will help keep the soda fizzy longer and I think that by squeezing the bottle you’re allowing for the gasses to escape the liquid soda and are giving them more room, thus re-expanding the crushed bottle. So, a question arose in my brain: Who is right?

The last thing I can claim is to be too knowledgeable about Science.  I proved just last night that I know basic Science stuff by passing an 8th grade Science Test on Facebook.  I got 14 of the 15 questions right!  Go me!  But that’s not what I came here to talk about.  I have friends that are far more knowledgeable about this stuff than I am.  However, I can research.  I did research.  And you know what I found?  More confusion.  Lots of talk about CO2 and expansion rates and partial pressure and ideal gasses.  Yikes! 

But as I read through some of the discussion board threads, it seems like folks are adamant about their answer. Some swear up and down that squeezing works and other’s claim that’s just stupid – like me.  Except with science-y stuff to back up their claims.  And I’m not smart enough to understand it or know who is right.  Let me present a less science-y example that I came across: 
My wife does this, and I cannot understand how it would be beneficial.  How might this keep the gasses from escaping?  She says it’s about having less air inside the bottle.  Please explain to me how this could be.  [posted by dammitjim to Home & Garden]
Here are a couple of the immediate responses to this question: 
Squeezing the bottle accomplishes exactly the opposite of what your wife wants to accomplish.   Squeezing the bottle creates negative pressure inside the bottle because of the plastic’s elasticity that will hasten the extraction of the carbon dioxide from the soda.

That is why the caps that claim to save carbonation increase air pressure instead, although they do not work as advertised because pumping air into the bottle does not force carbon dioxide back into the soda.  You would need to pump carbon dioxide into the bottle instead.  The bottles are pressurized with carbon dioxide when bottled, so once you open the cap for the first time, it’s a losing battle.  The best thing to do is keep the bottle in the fridge.  A colder soda will release less CO2.  [posted by Tanizaki]
I don’t think this actually works.  I’ve heard of people doing it before so I tried it for a while, but it seemed to have no effect whatsoever on how quickly the soda went flat.  The CO2 just doesn’t want to be in solution once it has all that lovely air to mix with.  I noticed the few times I did this that after a few hours, the bottle had expanded back to its original shape.  Obviously this could not happen if the CO2 was staying in the solution.  There’s just not enough pressure in the bottle to keep the CO2 in place once the seal is broken, no matter how much you squeeze the bottle.  [posted by katyggls]
Maybe I’m partial to these responses because they seem to be in line with my exact thoughts.  Admittedly, I haven’t gone to the end of the Internet and back seeking enlightenment on this subject, but I still think I’m right and I think hubby (love him though I do) is 

Does anyone want to weigh in on the subject?  I’m open to scientific responses presented in a non-confusing way.  Remember, I’m a person of somewhat average intelligence and if you get all science-y on me my ADD will rear it's ugly head and I’ll tune out and simply continue to think that I am right when, in all probability, I am wrong.


Home Physics Filter: Does squeezing the bottle of a carbonated beverage help keep it from going flat?

The Straight Dope: Fighting Ignorance Since 1973 (It’s taking longer than we thought): Does Squeezing (and sealing) a soda/soft drink bottle keep it carbonated for longer?

1 comment:

Tom said...

Squeezing the bottle will help the beverage go flat faster. Here's an experiment to help prove it. First, as mentioned elsewhere, the CO2 wants to be out of the liquid. That is the reason for tightly sealing the bottle to start with. But, the experiment is to empty the bottle halfway in two bottles then put the lid back on as tightly One of them just close the lid back on tightly, shake vigorously and set aside, for now. With second bottle, squeeze the air out and then shake vigorously then set aside. The shaking accelerates the release of CO2. Wait about 10 minutes (so that you don't get sprayed. Then open the lids, seal them again (after squeezing the same bottle), and repeat the shaking and waiting. Then, open the lids a second time and pour some drinks. The bottle that was squeezed and shaken (twice) will taste obviously "flatter". The sealed lid of the "un-squeezed" bottle will slow down the release of CO2 from the beverage. If, after opening a bottle and consuming some, the beverage was placed in a smaller bottle and tightly resealed, it would last much longer.