Why The Big Mac Has 3 Buns — And What Each One Is Called

McDonald's Big Mac has been a staple of the fast food chain's menu since it was first introduced in 1968. Yet despite how many times you may have ordered this classic sandwich, you likely never thought about why it has three buns — or what each one was called. When Jim Delligatti suggested a bigger burger to McDonald's corporate in 1967 in an attempt to capitalize on similar offerings from other competing fast food restaurants, he was told that he could experiment with creating one, but could only use the ingredients he had on hand at his Pittsburgh franchise restaurant.

Delligatti ended up ignoring that caveat, special-ordering a larger bun that was cut into three pieces. He did so because, unlike the Double Cheeseburger, the Big Mac was a heftier burger with more ingredients. The center bun holds them together so the sandwich isn't too messy to eat comfortably. It also maintains separation between the fresh, crispy veggies and the hot burger. The bun absorbs the heat from the meat, and the veggies create a barrier between the sauce, juices, and bun. This prevents the lettuce from getting gooey and wilted and the bun from getting soggy.

The three layers of this bun also have unique names: The crown (top bun), the club (middle), and the heel (bottom). The club layer, or center bun, isn't just another bottom piece or heel. Instead, the bun is created from slicing a larger, thicker brioche hamburger bun into three pieces rather than two. The middle piece is likely called a club because of the club sandwich, which also requires an extra piece of bread to hold all of the ingredients together.

If you've ever tried to take your first bite out of an oversized sandwich or burger only to have one of the pieces of bread slide off, taking the ingredients with it and creating a huge, gooey mess, you understand the importance of the club bun to a McDonald's Big Mac. When Delligatti constructed the first Big Mac, before it was introduced nationally, it only had two regular-sized buns. He quickly determined that two standard hamburger buns just weren't going to cut it. A third center bun was necessary to stabilize the towering creation and support the added weight of all its toppings.

When a Big Mac is assembled, the bottom bun contains special sauce, onions, lettuce, melted American cheese, and one patty. The middle layer contains special sauce, more lettuce and onion, pickle slices, and another patty. Placed on top of the second patty is the top bun. This specific order ensures all ingredients stay in place while you eat. The three-bun system, and the order of the sandwich's construction, has remained consistent ever since – why fix something that isn't broken? In fact, the strict McDonald's burger rule employees are never allowed to break is the order of assembly of the chain's iconic sandwiches.

However, one fact you may not have known about the McDonald's Big Mac is that the type of bread used did actually change. For decades, the buns used for a Big Mac were standard sesame buns. In 2023 when the burger's recipe was upgraded, McDonald's switched to a softer brioche bun with sesame seeds, now simply known as the Big Mac Bun.