Burger 21

Burger 21 comes from Tampa and from a family that already knew how to franchise a restaurant. Mark and Arlene Johnston were behind The Melting Pot, the fondue chain Mark and his brother Mike had grown from a single franchise in Tallahassee into a national brand, and in November 2009 they started a burger concept under the same management company, Front Burner Brands. The first restaurant opened in Tampa in 2010 and the first franchise deals, for Orlando, followed in 2012.

The name refers to the size of the menu, built around twenty-one burgers across beef, chicken, shrimp and meat-free patties, and each burger on the board has a number: the plain one is No. 1, the 101. The beef is Angus, ground and pattied in the kitchen, and the burgers can be cooked to order. Beyond the classics, the menu leans on regional American flavours: Tex-Mex, Cajun blackening, Memphis slaw and fried pickles.

The fries are the other half of the visit. They come with a sauce bar of house sauces, from Thai ketchup and sriracha aïoli to a toasted marshmallow sauce meant for the sweet potato fries. Official calories for every burger and sauce are in the chain’s nutrition guide, and some of the bigger burgers run past a thousand.

A small chain: restaurants around Tampa, in northern Virginia, Georgia, Charlotte and Albuquerque, plus airport branches and a food truck.

• Dairy Queen (United States, since 1940). The ice cream chain that quietly sells a lot of burgers, especially in Texas. Also built on beef, bacon, jalapeños and heat.
• Slater's 50/50 (United States, since 2009). Half beef, half ground bacon, and a peanut butter and jelly burger for good measure. Also built on beef, bacon, avocado and heat.
• Farmer Boys (United States, since 1981). A Southern California drive-thru started by brothers from Cyprus. Also built on beef, bacon, avocado and cheese.
• Hero Certified Burgers (Canada, since 2003). A Toronto burger chain that built its brand on traceable, hormone-free Angus beef. Also built on beef, bacon, avocado and cheese.