A Guy vs. CO2

Matt:

Settle an argument I'm having with my wife. I say if you open one of those big plastic bottles of soda, pour out the drinks, then crush the empty part when you close it back up again, the carbonation will stay in the soda better because there's less room for it to escape to. My wife thinks I'm nuts but can't tell me exactly why it wouldn't work. We turn it over to you. I'm right, right?

-- The Bickersons, San Diego

On paper, you're a genius. Can you keep the soda bottle squashed? Probably not. That's the flaw in your plan. When you uncap the fresh bottle, the CO2 gas dissolved in the soda is freed like a flock of little birds. Recap it and the CO2 will continue to escape until the pressures above and inside the soda are equal. Unfortunately, pressure from the escaping carbon dioxide will reinflate the bottle before equilibrium is reached and keep the cycle going for a while. Those big jugs of soda have to be chugged if you want them to be crisp and sparkly. They start dying as soon as you uncap them. If you're desperate, you can slowly pour the soda into a glass jar with no headroom, then put on a top. But of course the agitation of pouring makes the carbonation flee even faster. Basically, you're doomed. And that's probably why the missus sneered at the idea. "Guy" ideas (and this is a typical "guy" idea) always sound great, but usually they're danged hard to pull off. But she'd let you find that out for yourself.