Whether tangy and sweet or thick and spicy, barbecue sauces are usually red. South Carolina’s leans orange from its signature mustard, while Kansas City’s sauce takes on a rust-like hue thanks to brown sugar or molasses. But Alabama’s regional sauce, with its white, creamy appearance, stands out from the crowd.

We have Big Bob Gibson, the pit master behind what became Big Bob Gibson Bar-B-Q in Decatur, Alabama, to thank for the convention-busting, and often overlooked, white sauce. It all began in 1925, when the 6-foot-four, 300-pound railway worker started smoking pork and chicken in hickory-fired brick pits on weekends. He served the meat on a makeshift table nailed to a sycamore tree in his backyard.

Chris Lilly, the executive chef and vice-president of Big Bob Gibson Bar-B-Q, and husband of Big Bob’s great-granddaughter, Amy, says Big Bob was always a fan of more traditional vinegar-based sauces. But the whole, split chickens that Big Bob slow roasted for more than three hours called for something special. They needed additional fat to keep them moist. So Big Bob created what was then a one-of-a-kind combination of vinegar, mayonnaise, salt, pepper, and a touch of lemon juice to sauce his ‘cue.

Thanks to his hickory-smoked meats, noteworthy sauce, and charismatic personality, Big Bob’s restaurant grew from his backyard to ever-bigger locations across Decatur, allowing him to quit the railroad and make barbecue—complete with his signature white sauce—full-time.

Though it may look like ranch, Alabama white sauce bears little flavor resemblance to the salad dressing. “It definitely has a tangy peppery flavor,” says Lilly, a 2016 Barbecue Hall of Fame inductee. “The vinegar gives it a punch of acidity. It cuts the smoke flavor and brightens up the flavor profile. The mayonnaise brings the tone down and keeps the chicken from drying out. The mayonnaise also brings the flavor together with the vinegar.”

Big Bob Gibson made his original white sauce using vinegar, mayonnaise, salt, pepper, and bit of lemon juice; you can now find variations of the sauce across Alabama.Courtesy of Big Bob Gibson's Bar-B-Q

Five generations of the Gibson family have joined in the barbecue biz over the decades, and they have continued Big Bob’s legacy. Their signature white sauce has carried the restaurant to accolades that include five wins at the lauded Memphis in May World Championship Barbecue Cooking contest (the latest of which was in 2017) and being named Grand Champion at the 2004 American Royal International Invitational Barbecue Contest.

Between the restaurant’s two locations, workers at Big Bob Gibson Bar-B-Q are creating some 25 gallons of the sauce a day. Every chicken that comes out of the pit is dunked in it after slow roasting. It’s also become a versatile table sauce. “People love to put it on pork, chicken, and smoked turkey. They use it to dip potato chips in and as a salad dressing,” Lilly says. (Big Bob Gibson Bar-B-Q ships their original, bottled sauce to grocery stores in some southern states and specialty shops across the U.S., but you can also order it on their website.)

Big Bob didn’t keep secrets in the pit room. Over the years, so many people have worked in the kitchens that they’ve carried versions of the sauce with them to other restaurants across the state—so much so that white sauce has become synonymous with Alabama. Depending on where you are in the state, you may find versions that incorporate sugar, horse radish, and cayenne pepper. Other restaurants also use it as a marinade and as a sauce for coleslaw.

Lilly has even seen Alabama white sauce on the menu at The Publican, Paul Kahan’s Chicago restaurant, where it was drizzled over char-grilled carrots, and at Gott’s Roadside, in Napa Valley, California, where it was slathered on a chicken breast sandwich. He’s also eaten it while traveling abroad from Australia to Ireland. And it all came from a backyard barbecue restaurant in Alabama. “I feel proud seeing it on other restaurant’s menus,” Lilly says, “from roadside barbecue shacks to white linen restaurants.”