Can homemade soda save you money?

Homemade cold drinks are a hot business in the U.S. these days. We bought more than 1.2 million carbonating devices -- chiefly SodaStream and SodaSparkle -- last year, according to The New York Times. 

Making fizzy drinks at home is nothing new -- the out-of-control seltzer bottle was a staple of silent-film comedies -- but it's now a lot easier to craft your own bubbly water, all-natural sodas or knockoffs of popular pops like Coca Cola and Dr Pepper.

It's pretty simple: Pour water into the special bottle (it withstands the pressure), add carbonation and, if you like, flavor the result. Depending on which kind you buy and what's included (e.g., how many flavor mixes or cartridges), expect to pay anywhere from $60 to $170.

SodaStream cartridges are refillable and cost about $30; if you trade them in at the retailer a replacement cartridge will cost about $15. SodaSparkle's one-time-use cartridges cost anywhere from 53 to 70 cents apiece.

Can such devices save you money? That depends on whom you ask, and on what you want the machines to do for you. In fact, some people don't care whether they save moneyt.

Joshua Dorkin of BiggerPockets has never done the math. He bought the SodaStream to reduce his dependency on commercial soft drinks. Now he drinks homemade seltzer for a treat, instead of popping open can after can.

"I really saw this as a way to force me to be healthier…I'm already consuming less sugar and junk calories," he says.

An analysis on the DrPennyPincher blog indicates that SodaStream beverages cost 2.96 cents per fluid ounce. To produce the equivalent of the eight-pack of 12-ounce bottled soda that the good doctor's wife prefers costs $2.84, a savings of $1.16.

"With the cost savings plus the convenience and fun of making soda at home, as well as reducing plastic consumption, Sodastream has some advantages," he says.

KB of the Natural As Possible Mom blog reports that the "Sparkling Naturals" flavors work out to about $1.66 per liter. Some folks might blanch at the cost, but blogger Karen J. Bannan notes that "it's about the same" as the natural sodas she buys for her husband at Whole Foods -- and the smaller bottles never go flat and get thrown away, the way 2-liter bottles sometimes did.

She's definitely saving money on her own preferred beverage, natural flavored seltzer: "MyWater Essences cost $9.99 and make 60 liters -- very cost-effective."

Not everyone saves
But blogger Tim Owens ran the numbers and came to a different conclusion. "At the end of the day the SodaStream only saves you money if you regularly buy name-brand can soda and typically pay full cost," he writes in a post on his eponymous website.

On the other hand, Owens sure doesn't miss "lugging 12-packs of soda from the car" and also notes that his family no longer leaves half-finished soda cans to go flat.

A brand-loyal soft drink user might not care for soda machines' approximations of popular pops. Over at the Preaching to the Perverted website, a blogger named Dave found most SodaStream flavors "somewhat lacking," especially that of his beloved Diet Coke.

His advice? Buy a variety pack of mixes, which has samples of 12 flavors. "You can try them before you commit," he says in a post called "Now I'm carbonating everything."

Ketchup soda, anybody?
Some users prefer to make their own flavors. Dave is one of them, and warns that this can be messy since some liquids react rather explosively to carbonation.

"I fully endorse experimentation, just be prepared to do some cleanup," he says.

Putting anything other than water into the bottle could void the machine's warranty, according to the New York Times article. This doesn't stop the adventurous from fizzing-up liquids such as wine, liqueurs and centrifuged tomato juice.

That last one was a bust, incidentally; it came out tasting "like ketchup soda." But homemade sodas can include ingredients such as fresh lemon -- seldom used in bottled drinks due to the short shelf life of the fruit's acidity -- or real ginger. The adventurous are also infusing wine or vodka with herbs, fruit or even chili peppers.

Besides, warranties don't seem to matter to a certain group of soda-makers: They're using an adapter to allow the SodaStream to accept paintball C02 tanks, which are considerably cheaper to refill. Owens, who notes that paintball tanks are currently used by home brewers, says the $60 adapter will pay for itself within a few months and then allow him to "enjoy much cheaper C02 costs going forward."

So should you buy a soda maker? That depends. How much soda or flavored seltzer does your household really consume? Does that consumption vary enough -- mostly in the summer when you're entertaining, say -- to make buying on-sale commercial soft drinks a better bet?

Be realistic about this, or the soda maker could become this years Fad Device: used a while and then relegated to a high shelf in the pantry, right next to the countertop deep fat fryer and the mini-cupcake bakery. They all seemed like good ideas at the time, too.

More on MSN Money:

• NYC soda ban falls flat
• 12 everyday essentials you can make
• Morning coffee for $124 a pound
• How to re-grow your grub