Joe Raedle/Getty Images Pepsico CEO Indra Nooyi.
"The original Pepsi, the original Sierra Mist, they are all great tasting products," Nooyi said at Beverage Digest's "Future Smarts" conference in New York City. "When I go to make my own it is very hard to replicate the taste."
She also said that the brewing process takes too much time for a sub-par taste.
"People taste the product at home and say it doesn't taste as good as Pepsi ... and [it] takes too long," she said.
PepsiCo is currently testing half a dozen flavored products for SodaStream in various markets in Florida.
Nooyi's remarks may have been a subtle jab against PepsiCo rival Coca-Cola, which is partnering with Keurig Green Mountain to launch a SodaStream competitor with Coca-Cola-branded products.
Executives from Coca-Cola and Keurig also spoke at the conference Monday.
When asked about the Keurig partnership, Coca-Cola Refreshments President Paul Mulligan called it exciting and said he was confident there would be a market for the Keurig Cold machine.
But Hank Flint, the president and COO of Coca-Cola Bottling Consolidated, seemed less enthusiastic about the partnership.
"I don't know why [consumers] would fix a single [Coca-Cola drink] in a pod when they can have an eight-ounce glass right out of the fridge," he said, echoing Nooyi's remarks.
Nooyi said soda companies should come up with new flavors instead of trying to replicate existing beverages if they want to be successful with products for at-home soda brewers.
PepsiCo's SodaStream test flavors include Pepsi Homemade, Pepsi Homemade Vanilla, Pepsi Homemade Wild Cherry, Sierra Mist Homemade, Sierra Mist Homemade Peach and Sierra Mist Homemade Cranberry.
Pepsi and Coca-Cola are fierce competitors.
When Susan Neely, the CEO of the American Beverage Association, was asked during the conference whether it's difficult to get the two companies to work together on initiatives, she answered bluntly, "The cola wars are alive and well."