This undated product image provided by Taco Bell, shows the company's new waffle taco. The fast-food chain says the waffle taco, which includes scrambled eggs, sausage and a side of syrup, was the top seller during breakfast hours at the five Southern California restaurants where they were tested earlier this year. (AP Photo/Taco Bell)

NEW YORK (AP) -- Taco Bell says it's expanding its small test of waffle tacos, as it prepares to take its breakfast menu national sometime next year.

The fast-food chain says the waffle taco, which includes scrambled eggs, sausage and a side of syrup, was the top seller during breakfast hours at the five Southern California restaurants where they were tested earlier this year. Now the company wants to see how it would fare on a bigger scale; the waffle tacos and a full breakfast menu will be expanded to about 100 restaurants in Fresno, Calif.; Omaha, Neb.; and Chattanooga, Tenn., starting Thursday.

Brian Niccol, president of Taco Bell, said the idea is partly to get a better sense of how well restaurants will be able to handle the added operational pressure from the waffle tacos.

"You only get one shot when you go with big items," he said.

Taco Bell already offers breakfast at about 850 locations in 10 Western states and has been tinkering with new items such as the waffle taco before rolling it out to its 6,000 U.S. locations. Also being tested in the additional locations starting Thursday are a yogurt parfait and oatmeal.

Taco Bell isn't alone in trying to serve food in different parts of the day. Since restaurant chains are already paying for fixed costs of such as rent and electricity, the thinking is that they want to ring up as many sales as possible throughout the day, not just during the busy lunch and dinner hours. In industry jargon, executives often refer to this concept as "expanding dayparts."

McDonald's, for example, has been testing an "After Midnight" menu that mixes breakfast and lunch items. Taco Bell has also been promoting a "Happier Hour," which features snacks and drinks intended to attract customers in the late afternoon, when business tends to be slower.

Yum Brands Inc., the parent company of Taco Bell, clearly sees breakfast as its next big opportunity. In a conference call with analysts last month, Yum President Richard Carucci said that breakfast has accounted for about 4 percent of sales in restaurants where it's been available.

"But this is before we've now dialed it up," he noted.

Since they were introduced in March, the waffle tacos have undergone some tweaks, including the frying time and temperature, Niccol said. The shape of the taco, which has 460 calories and 30 grams of fat, was changed to make it easier to hold the stuffing.

If it does as well in the expanded test as it did at the five locations, Niccol said he doesn't see why it wouldn't be on the national menu.

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