Isn't it awful when someone's poured themselves a glass or so from a three liter bottle of cola and then when you want to drink some the next day it's gone flat?

Enter the Cola Refizzer.

Resembling an over-sized medicine capsule, and having a diameter just under the inner size of a bottle-neck, the Refizzer opens by unscrewing to reveal an empty inner-space.

A small quantity of sugar and yeast is placed within the bottom half, and warm water added until. The top half is placed onto the bottom half and the Refizzer is screwed back together. The walls, or at least some part thereof, are gas-permeable but do not permit the passage of fluid.

The Refizzer is placed into the bottle and the lid firmly attached. As the yeast ferments the sugar, Carbon Dioxide gas is released, building up pressure again, eventually recarbonating the cola. This part of the method is no different to the manufacture of sparkling wines in that the carbonation is by fermentation under pressure.

After a given number of hours the bottle is transferred to the fridge, still unopened, where it will stay fizzy until next needed.
-- vincevincevince, Sep 13 2007

Fizz Keeper http://www.jokari.com/fike2licap.html
Might not actually work (http://www.mekong.net/random/fizz.htm) [Karnuvap, Sep 13 2007]

Using yeast is not a good idea. They're slow. Also, I'm not sure how much CO2 you would get from a small "capsule" of yeast.

A much simpler, faster and better option would be to inject CO2 from a small cylinder, along the lines of existing carbonated drinks makers.
-- MaxwellBuchanan, Sep 13 2007


Baked in 'draught' beer in cans. They have a 'widget' filled with CO2.
-- marklar, Sep 13 2007


No, not baked. The idea posted was for a mini-fermentation chamber to generate the CO2 and re-carbonate a flat drink, not a CO2 reservoir to carbonate it. Not that I think it's a good idea, though.
-- MaxwellBuchanan, Sep 13 2007


The reason for the yeast-sugar-water combination is simple. Who has a spare cylinder of CO2 lying around ready to use? Yeast and sugar are very easily purchased and have virtually no cost at all.
-- vincevincevince, Sep 13 2007


Yes. Might just work. Would have to warm it up first though. To get useful amount of gas quickly you might need a lot of yeast, but then getting it to stop mght be a problem. Might just be an excellent time delay exploding cola bottle idea instead. Did I say might? Might. Might? Yeah, Might!
-- the dog's breakfast, Sep 13 2007


// Who has a spare cylinder of CO2 lying around // Anyone that buys one from Ace Hardware for $10-20 or has owned a Soda Stream or goes paintballing.

Perhaps you could use sodium bicarbonate (baking soda) with a very fine filter that only lets the CO2 out. This would probably have a weird reaction to the acid though.

Anyway, sugar on its own seems to do a pretty good job of making drinks super fizzy.
-- marklar, Sep 13 2007


//Anyway, sugar on its own seems to do a pretty good job of making drinks super fizzy.// Really? Tell me more!
-- vincevincevince, Sep 13 2007


//Perhaps you could use sodium bicarbonate // Now that *is* a good idea, [marklar]. Sodium bicarbonate plus phophoric acid (abundant in coke) will give CO2 plus, err, sodium phosphate (which is fine). Flavour should be unimpaired and fizz restored. Let joy be unconfined!
-- MaxwellBuchanan, Sep 13 2007


I can't believe there is a person that hasn't put sugar in a fizzy drink. Try it.
-- marklar, Sep 13 2007


Sugar makes the drink froth, but it does so by providing nucleation points for bubble formation. In this way, it actually reduces the fizz left in the drink. The proposal here (which is still a bad idea) is to put CO2 in, not take it out.
-- MaxwellBuchanan, Sep 13 2007


Sometimes I HATE the bakery. You sir, must be able to expirence my thoughts. I had this exact idea.

Damn you

<chucks pastrys in your general direction>

[+]
-- evilpenguin, Sep 13 2007


hmmm, perhpas an even more tantalizing prospect is some sort of "widget" that carbonates only what it pours (filtering through a CO2 combobulewhatsit) leaving the rest of the sugar water waiting it's turn to get fizzed. i'd buy that.
-- k_sra, Sep 13 2007



random, halfbakery