The Original McDonald's Filet‑O‑Fish Sandwich Was Made With A Tender, Pricier Catch

McDonald's Filet-O-Fish Sandwich has become a popular menu item among those looking for a relatively healthy, low-calorie, or high-protein McDonald's menu item. It's also a best-seller during Lent, when the fast food giant sells approximately 75 million sandwiches in one 40-day period. In fact, this religious observation is one of the primary reasons the sandwich was first added to the menu by Lou Groen, the owner of a franchise in Cincinnati, Ohio, in a neighborhood with a large Catholic population.

After noticing how sales decreased during Lent and seeing how other local joints succeeded with fish sandwiches, Groen developed his own version of a fast food fish sandwich, creating a "special batter" for the fish filet. His version used a variety of fish that was tender yet somewhat pricey for the time: halibut. "I wanted halibut originally," Groen told USA Today. "I was paying $2 a pound for halibut. That sandwich cost me 30 cents apiece to make." However, McDonald's wanted to sell the menu item for only 25 cents.

In the end, Groen was forced to replace his choice of halibut with Atlantic cod. Still, he maintains that his original "far outshines" the existing version of the sandwich. Nowadays, McDonald's uses Alaskan pollock, a species of cod, in its Filet-O-Fish Sandwiches, specifically wild-caught, sustainable pollock.

Halibut and Atlantic cod are both types of white fish; however, halibut has a denser and firmer texture that is more steak-like. Conversely, Atlantic cod are softer, flakier, and more delicate. While both offer a mild taste, halibut is considered more flavorful. It is known for having a slightly sweet flavor profile that is rich and buttery.

Because halibut is scarcer, it is also typically more expensive. Atlantic cod is more affordable and thus better suited for breading and frying. This is because breading and frying halibut has the potential to alter or destroy its flavor, whereas cod retains its shape well after being fried, becoming more tender. Additionally, cod typically has fewer calories and a lower fat content depending on how it is prepared, while halibut is rich in protein and omega-3 fatty acids.

If you're curious about which type of fish makes the best fast food fish sandwich, you can always experiment with both cod and halibut at home. Buy fresh cod and halibut and coat the pieces in a batter made with all-purpose flour, corn starch, baking powder, and any seasonings you prefer. Add light beer to the remaining dry batter mix and coat the fish again in the wet batter. Fry them in hot oil and then put each piece of fish on a soft, steamed bun with the veggies and dressing of your choice. Add a slice of American cheese for a true replica of the McDonald's Filet-O-Fish Sandwich.