As Shake Shack prepares for its initial public offering, another gourmet burger business is gaining momentum. That would be BurgerFi, a family-focused chain out of Delray, Florida, that's in such high demand, last year it enjoyed system-wide gross sales of $66.4 million, a 114 percent increase over 2013. BurgerFi is projected to double in size this coming year. 

From the outset it appears the not-so secret sauce is expansion. BurgerFi entered 12 new markets last year, including states in New England and the South, bringing its nationwide presence to 22 markets. The chain also opened non-traditional storefronts in family-friendly venues such as the Sun Life Stadium, home to the Miami Dolphins, and the CNN Center in Atlanta. 

Yet chief executive Corey Winograd doesn't point to expansion but to the restaurants' quality. Though over 50 of BurgerFi's units are franchised, each one relies on a single national distributor and a culinary director is responsible for monitoring all food vendors so meals remain above par. Dispatching regional managers to locations around the country has also been helpful in ensuring they learn best practices.  

A contemporary mash-up of burger joint and cafe, BurgerFi's ambiance is just polished enough to lure young professionals with money to burn and affordable enough for families in desperate need of a night out. "What's been happening for decades is people were accustomed to fast food, frozen patties, and not knowing or investigating what was in their food," says Winograd of the so-called better burger trend spurred by chains like Bareburger, Back Yard Burger, and b. good. "People want to know the the source of the food that they're eating." 

To that end, BurgerFi delivers, offering natural angus patties cultivated from cows free of growth hormones and steroids and some of the freshest, most local ingredients around. Burgers start at $4.97 and are served atop twice-buttered Martin's potato rolls.

This year, Winograd says the focus remains on expansion and developing more non-traditional storefronts for airports around the country. Up next: Ft. Lauderdale International. "Of course, there's always a risk of growing too fast," admits Winograd, who says he's not worried about diluting BurgerFi's eco-chic culture, "but when you have the right team in place and have a proven system," things tend to work out. "For us, the sky is the limit."