The Sauce Swap That Makes For A Tastier McDonald's Filet-O-Fish

The Filet-o-Fish is up there with the Big Mac as one of McDonald's classic sandwiches, even debuting nationwide three years before the franchise's signature burger in 1965. The iconic fast food chain always keeps the Filet-o-Fish on the menu, and it's been topped with tartar sauce since the beginning. But one of several McDonald's ordering hacks you'll wish you knew sooner shakes up the Filet-o-Fish by swapping out its tartar sauce for Big Mac sauce.

Word has been out for a while about what's in the supposedly secret Mac sauce, which often gets compared to Thousand Island. A look at the tangy and mildly sweet sauce's ingredients reveals the Filet-o-Fish hack actually isn't that unusual, since it can be viewed as leveling up its traditional topping. Here's why. McDonald's then-executive chef shared the Mac sauce's ingredients in a 2012 video: mayonnaise, sweet pickle relish, yellow mustard, white wine vinegar, garlic powder, onion powder, and paprika. Tartar sauce is often based around mayo and sweet pickle relish, and McDonald's version also contains onions, vinegar, capers, and parsley. It shares two of the Mac sauce's three base ingredients — mayo and pickle relish — and they both have forms of onion and vinegar. So you can think of Mac sauce as McDonald's tartar sauce with a boost from mustard, plus a couple of spices for a more complex flavor.

Another former McDonald's corporate chef has talked up the Filet-o-Fish hack on TikTok, calling it "delightful" and "money." He's also helpfully let people know they should ask for two shots of Mac sauce, since its gun dispenses less than the tartar sauce gun.

Once you try Big Mac sauce on a Filet-O-Fish, it opens the door to subbing in more of McDonald's sauces. The fish's mild flavor and the sandwich's few other ingredients – just cheese and a bun — act as a canvas for the sauces' flavors. It's why you can almost appreciate Mac sauce's contribution more on a Filet-o-Fish, since there are fewer flavor distractions than on a Big Mac.

McDonald's has six other dipping sauces you can try on the Filet-o-Fish: Tangy Barbecue Sauce; Creamy Ranch Sauce; Spicy Buffalo Sauce; Honey Mustard Sauce; Sweet 'N Sour Sauce; and Honey, which would be something really different on your fish. You could also bring some heat with the chain's hard-to-find Hot Mustard Sauce if you can track it down. Another option is the company's newest dipping sauce, which is debuting with McDonald's new McCrispy Strips chicken. Creamy Chili McCrispy Strip Dip is described as "savory, slightly tangy, sweet with a hint of chili pepper heat and a nutty toasted sesame finish" on the brand's website.

After you choose the sauce for your Filet-O-Fish — which you'll have to order in person because McDonald's won't let you switch its sauces on the app – try taking things one step further. Order fries with your fish sandwich, and use another simple hack to create a classic pub meal on a bun.