Money wasted.
Money wasted.
I almost always prefer drinking my own home-made soda to store-bought stuff, but I've given up completely on trying to formulate a recipe for a cola that tastes even remotely like people think cola should.
If you're deadset on making cola with a SodaStream, I'd go to a commercial restaurant distributor and get your hands on a box of real Coke or Diet Coke syrup.
Not at all. I brew my own cola at home using the OpenCola [1] recipe -- and speaking as a person who is very picky about colas, I find it delicious, easily on par with store-bought Coke -- which you could easily produce on a large scale.
The recipe is very close to the original Coca-Cola recipe; the Coca-Cola Company now presumably uses synthetic flavours in place of the various oils, which means the homebrew version actually tastes much more fresh and natural compared to store-bought Coke.
(I will admit Homebrew Coke lacks a little bit of the "bite" of Coca-Cola, which might come from the coca leaf.)
I use a SodaStream-style home carbonator, but it's not great. Store-bought soda water is much better.
For that matter, if you are dead-set on real Coke, you can buy bag-in-box syrups from your local distributor (or convince a neighborhood restauarant owner to sell one to you) and have real Coke products for less than SodaStream charges -- but you have to be willing to store the larger box and decant from it into something you can keep in your kitchen.