Wendy's pretzel burger has fast food aficionados’ mouths watering and it’s not even on the menu yet. McDonald’s may say “We don’t sell junk food,” but the company that once asked “Where’s the beef?” is hiding it in a salty snack and topping it with bacon and cheese. Thirsty anyone?

Wendy's pretzel burger has been getting buzz as one of the year’s most innovative fast food offerings. The fast food giant has been keeping details under wraps, because if Wendy's pretzel burger is a hit, other chains are sure to re-package their own offerings.

Wendy’s hasn’t announced when its pretzel bacon cheeseburger will be for sale. Wendy's previously test-marketed the pretzel burger in the Miami area.

In discussing, or not discussing, the national introduction, Wendy’s spokesman, Denny Lynch, said in an email "We're not sharing details of this sandwich today. It's not in any of our restaurants."

What junk food junkies do know is that the burger wrapped in a soft-pretzel-like roll could push Dave Thomas’ brainchild ahead of the competition.

Christopher Muller, professor of hospitality at Boston University's School of Hospitality Administration told media outlets "This could be a very, very big deal. I don't know why, but there's nothing else on the market quite like it."

Muller added "Wendy's hasn't had a new product like this forever."

Mark Brandau, senior editor at Nation's Restaurant News said that pretzels are on-trend, notes. He says the trend began at casual dining restaurants and has been working its way to fast food chains. All kinds of pretzel rolls are popular in Europe, especially in Germany. Blimpies put out a line of submarine sandwiches that are made with pretzel bread a few years ago.

Research analyst Mark Kalinowski of Janney Capital Markets was so optimistic about the new offering that he upgraded Wendy’s stock to "buy" from neutral, after test markets found that it could be one of the chain’s top-selling limited-time offerings in decades.

Wendy's has been testing recipes that use premium breads as a way to top the competition. The chain rolled out a Grilled Chicken Flatbread sandwich as a limited time offering earlier this year.

The burger is expected to be premium priced, which could hurt sales in a price-conscious environment.