That Half-Slice Of Cheese On Your McDonald's Filet-O-Fish Is No Mistake

McDonald's is not shy about adding cheese to its menu items ... except for its one seafood offering. Historically, the Filet-O-Fish is topped with only one slice of cheese cut in half. It may feel like a mistake, but McDonald's does this on purpose — the product description on the fast food company's website confirms that each Filet-O-Fish sandwich includes one "Pasteurized Process American Cheese Half Slice." While your first guess as to why this particular menu item gets less cheese might be for cost-saving reasons, it is actually done to maintain a delicate flavor balance.

When it comes to the McDonald's seafood option, the cheese doesn't exactly hang off all four sides of the square fish patty. In fact, the Filet-O-Fish cheese is known for sliding off – and with the company only giving out a half-slice per sandwich, we can't risk any of it slipping out the side. McDonald's spokesperson Julie Caturano told Journal Star that the sandwich is intentionally made with less cheese than usual because it "complements the taste, rather than overwhelming it." The tartar sauce on a Filet-O-Fish also carries a powerful flavor that may not mix well with too much cheese. Considering that most people would not ordinarily pair cheese with seafood, it makes sense that the sandwich would have slightly less cheese than other menu items.

The McDonald's Filet-O-Fish debuted in 1962 after a franchise owner saw an opportunity to appeal to a previously untapped market. As McDonald's itself says, the inventor of the sandwich wanted to offer a white fish option for customers to eat on Fridays, the day that people with certain religious affiliations avoid eating meat. The Filet-O-Fish was the winner of a race against the Hula Burger, a sandwich with just pineapple and cheese on a bun. The fish sandwich quickly rose in popularity and earned its place among McDonalds' many burgers and chicken McNuggets. Whether you're a Roman Catholic, a pescatarian, or just enjoy a nice fish filet, the limited fish option at McDonald's is a great meat alternative that has been a menu mainstay for decades. But the sandwich didn't always have that half slice of cheese.

The Filet-O-Fish was almost made with a different fish. Lou Groen, the inventor of the iconic sandwich, told the Cincinnati Enquirer that he originally wanted to use halibut for the fish patties. It wasn't until corporate told him he needed to switch to Atlantic cod that the half-slice of cheese was added to bring out the flavors in the white fish alternative. While Groen still claims that his original recipe is a far better sandwich, the Filet-O-Fish we know today is said to have saved his franchise.

The Filet-O-Fish to half-cheese slice ratio is a decision that most fans can get behind since the delicate distribution of flavors works well for the seafood sandwich — although many nay-sayers still turn their noses up at the idea of combining cheese and fish. However, cheese and seafood is not such an unusual pairing. Anyone who is a fan of shrimp Alfredo, tuna melts, or a creamy crab dip will tell you that the key to a cheesy seafood dish is selecting the right pairing of cheese and fish. 

McDonald's fish filets utilize a flaky white fish that has a mild flavor that is not too "fishy." This pairs well with the subtle flavors present in the creamy American cheese and tangy tartar sauce. The fast food chain switched from cod to Alaskan pollock in 2013 as a part of the company's "journey toward sustainable fish," according to McDonald's itself. Luckily, fans don't seem to mind, as the fish still pairs nicely with a half-slice of cheese. If you want extra cheese on your Filet-O-Fish, you will have to ask for it specifically, and it will cost you extra. If you request extra cheese, you will likely get a whole slice instead of the traditional half-slice.