How Does Chicago-Style Relish Get So Neon Green?

Different regions of the United States have their own favorite preparations of things like pizza and hot dogs, and these geographic spins conjure a lot of local pride. Case in point: The Chicago hot dog is its own unique treat, and Chicagoans take it seriously. There are plenty of facts that define the Chicago-style hot dog, many of which come down to its toppings. Ketchup is a no-no, but mustard is a big yes, the veggies are piled on in full force, and relish is a must. In fact, it requires neon-green sweet relish specifically. 

The relish on a Chicago dog tastes like sweet pickles with an acidic vinegar bite, so why does it look a bit like Nickelodeon slime? The answer is dye, but no, it's not green dye, and there's not much more reasoning behind the dye other than that it's fun. The flashy hue was made popular by the brand most closely associated with the Chicago dog: Vienna Beef. Per Forbes, Vienna Beef still has a 71% market share in Chicago, meaning any Chicago hot dog you get is likely to be Vienna Beef, and the company isn't widely available everywhere else, so it's uniquely Chicagoan. But despite its name, Vienna Beef doesn't only make the actual wiener — it also makes the relish that's become quintessential for the Chicago dog. Vienna Beef adds blue dye to its sweet pickle relish and, when mixed with the pickles and vinegar, the dye comes out as a brilliant green hue.

The blue dye might not affect the flavor, but it certainly affects the instantly recognizable look of a Chicago-style dog. Chicago hot dogs are referred to as having been "dragged through the garden" because of all their produce-aisle toppings, and neon relish is like a highlighter to that green veggie quality. 

In general, relish is any chopped up fruit or vegetable preserved in a vinegary sauce. The most common relish here in the U.S., aka the green one you get on hot dogs, is made with pickles. Depending on what kind of pickles are used, there are different relishes, like dill relish versus sweet relish. Chicago hot dogs specifically opt for that sweet relish, and the resulting taste of that sweetness with the heat, spice, sourness, and herbal freshness of onions, pickles, tomatoes, and peppers is as distinctive as the wiener's neon image.

The vibrant shade has become so necessary that now, even when a small, independent brand makes Chicago-style relish, they add dye and label the condiment as neon green. There are plenty of acclaimed spots in the Windy City where you can get an impeccable Chicago hot dog, and whatever brands these places use, you can count on finding a sweet, tangy, delicious relish that happens to look just a little radioactive.