Cold-brewed tea soda (food)
A while ago I got a SodaStream water carbonator to replace my slowly-failing iSi siphon. While I haven't used any of SodaStream's own flavor syrups (as I have heard they are generally nasty, and all of them use sucralose which tastes bad and whose health "benefits" are questionable at best), I have of course made several bottles of soda flavored using Torani syrups. However, I found those to be a bit sickeningly-sweet, not to mention overpriced, but after a bit of experimenting I discovered a very simple means of making soda which is quite delicious and also much healthier: herbal tea!
Basically, after carbonating a 1L bottle as best as you can, put two herbal teabags in (I usually remove the tags and use chopsticks to remove them) and let it brew overnight. If the tea you selected isn't sweet enough, you can add a couple tablespoons of simple syrup or honey or the like afterwards.
I find that Tazo's herbal teas work very well; their orange blossom and passionfruit teas are way too fruity and sweet for use as a hot tea, but as a soda flavoring they're perfect, and zero-calorie, too.
Stash's lemon-ginger tea is also pretty good as a ginger ale surrogate, although that needs quite a lot of sweetener. (I've also found that it doesn't hold its carbonation very well.) Of course, for ginger ale there are better ways to brew it (which involve actual fermentation)
Comments
One thought: you might find a wider variety of ginger etc. teas at an Asian grocery (if you can figure out what the labels say).
-bill
Also I love the Wikipedia description:
That tendency to explode, while undoubtedly enhancing the Gas-o-Gene experience, also makes finding surviving units rather a challenge.
I've idly considered building my own, yeah
Without even running the numbers, I strongly doubt if a Gas-o-Gene could compete on cost effectiveness. The people who make those little CO2 cylinders are undoubtedly using CO2 that condensed as a natural byproduct during the distillation of oxygen and nitrogen from the atmosphere for use as welding and medical gasses. CO2 freezes out as dry ice before either of those gases liquifies, and the commercial demand for oxygen is way larger, so it's essentially a waste product.
CO2 is about 44g/M. So, 0.18M in an eight gram cylinder. 100 Leland soda chargers retail for about $37 (amazon.com), so $0.37 per cylinder, or $2.04/M.
The wikipedia article specified using baking soda and tartaric acid. Tartaric acid is about 150g/M. Baking soda is about 84g/M. Tartaric acid has two 'organic acid' functional groups, so one molecule of tartaric acid will react with two molecules of baking soda. It should be apparent, therefore, that 0.5M of tartaric acid combined with 1M of baking soda (with some water for the reaction to run in) will yield about 1M CO2.
We don't need chemically pure reagents for this - we can use USPS (food and drug) grade. Tartaric acid retails for about $10/lb, baking soda for about $2/lb (nuts.com).
1lb = about 454g, so (75g tartaric acid/(454g tartaric acid/$10))=$1.65, and 84g baking soda/(454g baking soda/$2))=$0.37.
You're going to pay, then, about $2.02 per mole of CO2 evolved, or about $0.37 for 0.18M CO2. Astonishly, the Gas-o-Gene costs just about the same to operate.
SodaStream is still a bit cheaper at ostensibly $.25 per liter's worth of CO2, although I'm not sure how much to believe that number.
http://www.amazon.com/100-Leland-Soda-Chargers-Seltzer/dp/B00304SLAO
-bill