Do-it-yourself beverage maker SodaStream International (SODA) acts as effervescent as its soda concoctions these days, as continuing rumors of an impending buyout by Starbucks (SBUX -0.96%) buoy its stock off its lows. But the coffee slinger has indicated it has its own plans for the future, and they may not include the partnership that the soda maker's investors are counting on.

After reporting earnings last week that showed profits jumping 10% to $427 million, or $0.56 per share, and revenues that were up 9% to $3.87 billion, CEO Howard Schultz said Starbucks would be launching its own handcrafted carbonated beverage, called Fizzio, to 3,000 locations in the U.S., with additional debuts across Asia and Africa. Is this the big soda deal that's been rumored to break, and did the idle gossipers misconstrue what was being discussed?

Source: Starbucks.

Certainly Schultz is positioning Starbucks to be more than just a cool place to grab a cup of coffee. Beyond just food, which has proved to be especially popular as it widens its market to breakfast, lunch, and dinner, Starbucks is further broadening its appeal by extending its drinks business to include beer and wine, juice, and now soda.

A compelling case could be made (and has been) that it wants to meet your beverage needs by going beyond just its myriad corner coffee shops and grocery stores, and reaching into your kitchen as well, with an acquisition of the DIY soda appliance maker. Even the latest scuttlebutt that it's deep in discussions to take a 10% piece of SodaStream seemingly has merit, as Coca-Cola recently took a similar-sized stake in Keurig Green Mountain to introduce its own home-based branded beverage system.

Yet SodaStream's performance has underwhelmed Wall Street lately, with sales for 2013 rising by double-digit percentages to $563 million but adjusted profits coming in below $53 million, much less than the $65 million analysts anticipated. As management doesn't anticipate that 2014 will allow it to escape the "headwinds" it's already experiencing, it raises the question of whether Starbucks would want to partner with the runner-up simply for the sake of saying it also has a place in the home cold beverage market.

It's clear that Coke viewed all the participants in the niche and found SodaStream lacking. That it chose to go with the coffee maker instead suggests that it feels there is one dominant leader of DIY home appliances, and it wasn't the soda maker. I don't see Starbucks jumping on the "me, too" bandwagon when Schultz will be focusing on his company's own soda brand, and I've already expressed concern that SodaStream's controversial base of operations in the Middle East may be something Starbucks and other potential partners might want to sidestep altogether.

The latest reports say Starbucks only wants a piece of SodaStream International, and that could be a more likely scenario than an outright acquisition. Coke's stake in Keurig validates the home beverage niche, but with Fizzio set to launch this year, there may be no need for Starbucks to bother taking on an investment in an underperforming competitor at this point.