To keep soda fresh, is it better to squeeze excess air out of the bottle before sealing it?

Question

I think it will keep the fizz in longer, by reducing the air in the bottle, my hubby says that squeezing the bottle creates negative pressure in the bottle which will pull the carbonation out of the soda. Who's right?

And we don't fight about it every time, we talked about it once, and i was curious.

Answer 1

Well hubby is mostly right, but your idea of reducing air in the bottle is not that far off..

The problem with squeezing the bottle, is exactly the negative pressure created because the bottle wants to return to its natural shape.

What should work better is if you add something to the remaining liquid, i.e. marbles so that you fill the bottle completely with the remaining liquid before closing it. Of course even doing this the drink will eventually get flatter and flatter just because of the agitation everytime you open it.

In order to keep it really crisp you must replace the CO2 that has been lost. The dry ice method will work, but somewhat impracticle. A better approach would be to rig something up to a BB gun type CO2 cartridge, and repressurize the bottle with CO2.

Note that I have seen gimicks sold which let you pump the bottle up with air to pressurize it. I don't think these will work because the partial pressure of gases are independent from each other. I.e. even though the bottle is pressurized with air, the CO2 amount is low in that air.

Answer 2

Your hubby is correct!
if you want to really keep "The Fizz" longer you put an expanding stopper on the bottle and drop a piece of dry ice ( CO2 ) about the size of a peppercorn in the bottle before you install the stopper. Due to the sublimation properties of CO2 the drink will not be contaminated and the Fizz will definitely be there.
Note: Sublimation is the physical characteristic of changing from a Solid to a Gas without first going Liquid!

BIG NOTE~! If you use too much Dry Ice the bottle WILL EXPLODE or BLOW the STOPPER out and Possibly cause GREAT BODILY HARM.
This is not something you would want your kids to fool around with! ! ! !

Answer 3

The way they get carbonation into the soda in the first place they use a large amount of pressure.
by keeping the air in the bottle you are keeping a higher air presser on the soda itself and the carbanation will stay in longer.
By taking the air out of the bottle you are putting the soda in a low pressure area and the carbonation is more likely to escape.

Answer 4

Do not reduce the air. That will only cause the fiz to come out of the soda. The higher the air pressure in the soda bottle, the better! It would help keep the Co2 from comming out of solution.

Answer 5

Your husband sounds right. I think that CO2 should leak out of the liquid until the partial pressure of the CO2 gas in the air space in the bottle is equal to the partial pressure of the gas dissolved in the liquid.

Just put the lid on tight, so that the carbonation cannot leak out, and keep it in the fridge (gases stay dissolved in liquids better if the gas is kept cold).

Answer 6

He is right! Notice that when you first open the bottle, much gas escapes. Next time you open it, it is flatter than when first opened. The reason it is pressurized in the first place is that the excess pressure keeps the CO2 dissolved.

Answer 7

well, i think it might just be pushing out all the air and CO2, because all of it is in there anyway. heres my advice, get cans, because no matter what you do, the bottled sodas dont stay fizzy. also, if you have an argument with your husband every time, its time to call a truce and forget about it. seriously, its soda. its fizzy sugar juice. try something healthy, like juice or smoothies.

Answer 8

Your husband's right.

Next time you're at the store you should try looking at the cans. They're usually only slightly more expensive, and it's worth it. Next time you're at the store, look at the "unit price" on the price label. The unit price for soda is "price per ounce", so you know how much you're paying per ounce, and you can use that to compare between the different forms.

Answer 9

Hubby

Answer 10

Your hubby says right.