The One Ingredient That Actually Isn't In McDonald's Big Mac Sauce

McDonald's is one of the most iconic restaurants in America, and there's definitely no more iconic product on its menu than the Big Mac. Most people have probably eaten at least one in their lifetime, and thanks to that ubiquitous '90s jingle, you may have the ingredients memorized: "Two all-beef patties, lettuce, cheese, pickles, onions, on a sesame seed bun." Perhaps no other food commercial in history has burned its way into our memories.

But, on that list of Big Mac ingredients, there's one that clearly stands out: the special sauce. The question of what's in the special sauce has vexed consumers for decades now, ever since the debut of the Big Mac in Pittsburgh, Pennsylvania in the late 1960s. But while we may not know what exactly is in the mixture, we know one thing that definitely isn't: ketchup. So, if you're making an at-home Big Mac sauce substitute with ketchup, you might be doing it wrong.

People have been trying to recreate Big Mac's special sauce for decades, both at home and in restaurants. Much like Coca-Cola's recipe, McDonald's has never revealed the intricacies of the ingredient list — and why would they? Not only is it a huge draw to the chain but the company is known to respect propriety to the point where even the method they use to store and serve soda is unique to them (yes, McDonald's sodas really do taste different for this reason).

Some might think the special sauce is just Thousand Island/Russian dressing, but that's not quite right. The Big Mac topper is definitely similar to those two, but not quite the same. It has way more pickle relish than either of them, and there's another ingredient (or ingredients) that can't quite be placed.

But, what we do know is that the mystery ingredient isn't ketchup. Mike Haracz, a former McDonald's corporate chef, has been sharing info about the company for a while now on his TikTok feed. One of these videos was a stitch involving a woman who claimed to be making homemade Big Mac sauce using a base of ketchup, mustard, and mayonnaise. Haracz had only one comment: "There's no ketchup in Big Mac sauce." Now we know!

Interestingly, while McDonald's ketchup may not be featured in its Big Mac sauce, the condiment itself is also unique from other chains — much like the Big Mac sauce and seemingly everything else the company does, it's proprietary. So, yes, much like the sodas served at the Golden Arches, McDonald's ketchup really does hit different from other brands.

Both McDonald's and Heinz have labels that list ingredients like tomato concentrate from red ripe tomatoes, distilled vinegar, high fructose corn syrup, water, salt, and "natural flavors." But McDonald's stops there, while Heinz adds onion powder and other spices they won't name (it's not just McDonald's that gets secretive about their recipes). And it might be way McDonald's ketchup has both that brighter red color and a slightly more tomato-y flavor.

While we may not know — and probably will never know — what's in the Big Mac sauce, we know that bright red ketchup isn't a part of it. We'll just have to survive without that knowledge.