I hope this question is appropriate for the Physics SE, although it involves a practical situation rather than inquiring purely about theory.
I've been trying to create carbonated water at home using a contraption involving two bottles connected by a tube; one is filled with the water to be carbonated (with the tube going almost all the way down), and the other has a mixture of citric acid, sodium bicarbonate and some water to dissolve the two (with the tube inserted just a bit lower than the cap).
The idea is simple, and has apparently been employed successfully by many people following an online tutorial (which otherwise used white vinegar instead of citric acid): produce CO2 that will go from one bottle to the other, while you're consistently shaking the water bottle to help dissolve the CO2. The tutorial said to do the actual carbonation until no more bubbles come out (probably around 30 seconds), give it another final shake and then let it sit for another minute, and finally open the carbonated water bottle while pinching the tube (supposedly it also helps keeping the CO2 in the water, but I think in practice it's only so you won't accidently have the acidic mixture from the other bottle spray into the drinking water).
I tried it several times using about 1.5tsp of sodium bicarbonate + ~equal amount of citric acid, and the water isn't left with any discernable fizz. I didn't find any smaller bottle, so the acid/sodbic bottle is 0.5 liter while the water's is 1 liter. The bottles already get quite stiff due to pressure (and I'm not sure how much more simple plastic bottles can withstand), but perhaps the pressure produced in practice using appliances such as Soda Stream is much higher, and nothing is dissolved in my experiment because there's simply not enough pressure? On the first attempt it shot the water all over the place when opening the bottle; on the last attempt, while opening carefully, nothing seemed to visually escape from the water but they were fizzless.
I used ice-cold water as advised.
Any suggestions? I did some calculations and the amount of CO2 produced from ~1tsp citric acid+1tsp sodium bicarbonate should at least nominally be enough to make 1 liter of water appropriately fizzing, if all of it were dissolved.