Why McDonald's Filet-O-Fish Comes With A Half Slice Of Cheese 

McDonald's Filet-O-Fish sandwich is fast food royalty. The magical marriage of a soft steamed bun, flaky, real-deal fish, a tangy touch of tartar sauce, and gooey cheese is unquestionably legendary. However, like most legends, the Filet-O-Fish also raises some questions — for example, why is it graced with a mere half slice of perfectly melty American cheese? This cheesy moderation strikes many Filet-O-Fish lovers as strange, especially considering that all of McDonald's other cheese-laden sandwiches contain a full slice.

According to McDonald's, the reason is simple — that's how it's always been done, and it tastes better that way. The company claims that it still follows the same recipe created by franchisee Lou Groen in 1962, which, apparently, called for only a half slice of cheese. In response to curious customers, McDonald's has written on X that this scant cheese serving is meant "to save on the flavor of the sandwich." Interestingly, the European version of McDonald's Filet-O-Fish is completely cheese-free.

If McDonald's rather vague explanation for why the Filet-O-Fish only comes with a half slice of cheese leaves you wanting more, don't worry — the internet has juicier theories. Some suggest that the original Filet-O-Fish created by Lou Groen contained no cheese. When McDonald's agreed to put the sandwich on the permanent menu, it switched halibut for a cheaper whitefish and added the half slice of cheese to compensate for, but not overpower, the milder fish. In the vein of saving money, many argue that using only a half slice of cheese must be a cost-cutting measure.

However, many sandwich theorists posit that the Filet-O-Fish comes with a half slice of cheese because a full slice would overpower the fish and result in an imbalanced flavor, and a half slice is the optimal portion to contrast with the tangy tartar sauce and suspiciously golden crispy fish filet. In other words, Mickey D's isn't being stingy, it's just trying to give us the best culinary experience. Luckily, if you'd like to test this theory for yourself and try a full slice of cheese on your Filet-O-Fish, it's more than possible – just ask for extra cheese (and while you're at it, consider trying these other brilliant Filet-O-Fish hacks).