OKAY!!!! This doesnt work. For those of you who tried and got flat soda still, here is why. It deals with chemistry in the respect of Dalton's Law of Partial Pressures. Initially your soda comes with a certain amount of CO2 that is dissolved into the liquid soda. When you open the cap, some of that CO2 releases from the liquid into the atmosphere. You drink some, with some soda left. You cap it, and as the soda sits, the CO2 left within the liquid releases and fills in the space above and slightly pressurizes the system. Now the problem with adding just air is that air has different solubility properties than CO2, therefore you are simply pressurizing the volume of gas above the soda, not the soda itself. This is why it still is flat upon reopening the bottle. The only way you can recarbonate your soda is to completely remove all the air from the system when you recap the bottle, then add CO2 only. This will recarbonate the soda, although not to the extent that it is when you first buy it. As you add pressure to the system by adding gas, and only the one gas (CO2) is involved, the gas becomes more soluble in the liquid soda, thus carbonating it. Different gasses have different solubility properties. Air isnt the same as CO2. Thus this technique will not work.

long time no coment, but i will use this $1 for 3 leader $5 for a 12 pack

Can I use this to make seltzer water?

I bought for about 3 bucks a cap with a pump and just screw it on and pump it. Does not taste like black butyl rubber, yeck. But it like this probably will make soda taste flat in the end. You are pumping a lot of non CO2 gas into the bottle, it permeates the soda and it still taste flat . What was nifty though was my friend (as a kid) did this to a water pistol and made a pressurized squirt gun before pump up water guns were made. He was a diabetic and used syringes. What a hoot.

Do you have to take the cap off before you pour or does the cola somehow go through the cap?

Good Idea I will have to try it some time.
  BTW I don't see all the fuss about the nails some people just naturally have fast growing strong nails. Jealousy is they only reason I can see for fussing about it.
 Of course having nails like that has its drawbacks as well, like breaking the nail clippers ( my husband has strong nails like this and has broken nail clippers before). anyways thank you for the instructable.

Mine tasted like rubber and didn't carbonate. Any tips?

mine is rubber. will this work?

Where did you get the tire valves?

Mine doesn't have the washer or the nut. Is this okay?

Why can't you use a short cap?

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Or you could just drop a chunk of dry ice in and SHAKE SHAKE SHAKE!

Great idea and instructions are very easy to follow. Well done. Thanks

THANK YOU! I can almost always find 2 liter bottles on sale and cheaper than a 12 pack of cans! Can't wait to try this!

hey could I fill a bottle with just air only and use it fire stuff? thanks chris

does this re-carbonate your drinks too?

good idea! I like to keep things fresh...if you know what I mean

Cool concept. Isn't this a video about soda? You'd think it was a poll on whether or not this guy should trim his nails.. :) Who cares?

Cool, thanks for sharing

Nice. I've been doing something similar using icemaker tubing, inline valves and a CO2 tank. I might have to try a tire valve instead.

Is there any danger of oil from the compressor being introduced into the soda?