For a while we had our cola on tap in the office (and we'll probably do it again). We used the same carbonator system we use for the beer tap, which is basically a CO2 tank hooked up to the source liquid, like this [1], and which injects the CO2 into the water on demand. It's the same principle used in soda fountains. It doesn't scale to real bottling operations, though.
As for the article, I disagree that "the soda stream carbonation doesn't really produce the desired effect". I have an off-the-shelf carbonation system that's similar to SodaStream, and it works really well. But these units vary a lot in carbonation quality, so it may be that the author of the article did not have a good enough carbonator. The important factor is the size of the bubbles; smaller bubbles means they last longer and provide a "fuller" effervescence.
[1] http://www.popsci.com/diy/article/2012-06/how-make-your-own-...
I built this: http://imgur.com/YLraTl8
Part list:
http://www.beveragefactory.com/draftbeer/tanks/co2/C20.shtml http://www.beveragefactory.com/draftbeer/regulator/double/bf... http://www.beveragefactory.com/draftbeer/home_brew/kegs/lbc0... http://www.beveragefactory.com/draftbeer/couplers/homebrew/B...
You'll also need some 5/16 ID hose, you can use un-reinforced vinyl from a hardware store. And 2 hose clamps.
You can fill the tank for about $20, and it's good for 1,000 liters of seltzer.
It also works great for apple juice, iced tea, lemonade. Anything you like.
In short, it says that you need to remove the air inside the bottle before carbonating, and then carbonate over multiple passes while letting excess gas out of the bottle between the passes.
I have not researched the matter any further and can not make any claims regarding the quality of the information.
They fill a large tank with cold water and pressurized CO2, and mix. Then fill bottles and cap. It's a continuous process, so they pump water under pressure into the tank, and CO2 as well to make up for what they fill.