Honestly, Dirty Mayo Is Just A Rogue Aioli
It's funny how different food descriptors mean different things as they tend to vary from recipe to recipe. Take "dirty," for example. In the sense of dirty rice, it means rice that's been cooked with added ingredients such as meat, vegetables, and Cajun spices. In a dirty Shirley, on the other hand, the "dirt" is just straight-up booze. And, with the dirty mayo that once accompanied a burger served up by the 8oz Burger Company in Sheffield, U.K., the dirtiness was supplied by adding some additional spices and condiments.
Despite the fact that the establishment has sadly closed down, the recipe for dirty mayo lives on, thanks to "The Sheffield Cookbook" where it has been immortalized for all eternity — or at least as long as the print run lasts. It's basically a homemade mayonnaise that is flavored with sugar, yellow mustard, cumin, and smoked paprika.
While the 8oz Burger Company went with the "mayo" moniker, fancier foodies may have applied the term "aioli," instead. Unlike most aiolis, however, this one goes rogue by omitting that condiment's signature garlic. This feature, we feel, will very much appeal to any vampires in search of a burger topping less sanguine than ketchup.
Aioli wasn't always just flavored mayo
The 8oz Burger Company's vampire-friendly dirty mayo is definitely an aioli outlier due to its lack of an aromatic component, but it is still aioli-adjacent in the modern definition of that word. Garlicky though they may be, most of the condiments that fall under the aioli umbrella these days really do not differ all that much from mayonnaise in their basic egg-and-oil-emulsion base. "Aioli," in fact, is often used synonymously with the term "flavored mayonnaise." Our own homemade aioli recipe, like the 8oz Burger Company's dirty mayo, is flavored (and colored) with mustard and could, in fact, also be called "garlic-mustard mayo" or something along those lines.
Originally, however, aioli and mayonnaise were two completely different things. Early aioli (which dates back a few millennia) consisted of little more than olive oil and garlic and was entirely egg free. While the egg is generally allowed these days, even by aioli purists, there are some who insist that garlic should be the only flavoring involved. By their standards, the 8oz Burger Company's dirty mayo wasn't remotely aioli-esque, but we're less strict in our definition of the word so we're going with "rogue aioli," instead.