Keeping drinks fizzy

[edhesketh]

If you squeeze a fizzy drinks bottle before screwing on the top does this make any difference to how fast the drink goes flat?

[sft42]

I wouldn't think so...the best thing is to screw the top on tightly and store the bottle on it's side (or upside down) so that the gasses can't escape through the cap....that's what I was told though I fully expect someone now to prove me wrong :^)

[j2buttonsw]

There is a dynamic equilibrium between the gas in solution (making the solution fizzy) and the gas in the air above it. If you squeeze the bottle you are removing the air above the liquid and so forcing the equilibrium so more gas will go from the solution to the air. The best way is to pump gas into the bottle thus forcing the equilibrium in favour of keeping the gas in solution.

[bernardo]

It would make it go flat faster - the elasticity of the bottle would make the bottle try to go back to its unsquashed shape. That would provide more space for the air at the top to expand, which would result in a drop in pressure. Therefore it would be easier for the dissolved gas inside the liquid to escape from the liquid. It's a bit like being able to boil a kettle at colder temperatures if you are up a mountain where the atmosphere is thinner.

[edhesketh]

exactly what I wanted to know. Cheers for the info

[Lennon]

You can actually buy white caps with little pumps on the top, so you throw away the cap that comes with the bottle and then screw this cap onto it. Then you pump the tope bit up and down and it puts gas into the bottle as j2 says. My Nans got one - I think its from Betterware or somewhere like that.

[Janetex]

Is that what I'm supposed to do with those caps?????? Off to rummage in the botrtom drawer!

[Jaybee]

A couple of years ago Adam Hart-Davis did an experiment about this on TV, and found that yes, if you squeeze out the air from the bottle, the remaining drink stayed fizzier for longer. Apparently the larger the air space in the bottle, the more likely the dissolved CO2 was to dissipate.

[winemaker]

I agree with Jaybee, once opened, the pressurised liquid,in a Pet will retain more gas when air expelled by squeezing, prior to sealing with closure.