Why McDonald's Doesn't Serve Breakfast All Day

McDonald's breakfast notoriously ends at 10:30 a.m. at most locations.

Now, the brand $4 it might extend breakfast hours-though no specifics have been provided.

McDonald's already offers $4.

We reached out to an expert, Scott Hume $4 to find out why McDonald's hasn't fully capitalized on the breakfast menu's popularity.

Limitations in the kitchen hold the brand back, Hume told Business Insider.

"It's a shock to hear, but McDonald's doesn't do made-to-order breakfast," Hume said. "Its customer traffic is too great for that. So eggs and sausage are pre-cooked and held for breakfast sandwich assembly."

At 10:30, McDonald's needs to start using its toasters and grills for burgers, chicken nuggets, and sandwich buns instead, Hume said.

J.M. Owens, a McDonald's operator in Atlanta, explained more about the process $4 earlier this year: "First, there are some capacity issues. We only have so much toaster space and so much grill space. Unlike a lot of breakfast QSRs, we still cook our product on a grill. Many of the pretenders are doing a ton of prep in microwaves. For instance, go into a Dunkin' Donuts or a Starbucks, who are chasing breakfast, and you don't find a grill, or oven, or fryer. We prefer to be a restaurant rather than processing everything through a microwave."

"The 'McDonald's After Midnight' menu works when customer traffic is light," Hume told us. "But it wouldn't work all day because it requires streamlining both breakfast and burger menus to a few all-star items."

So, it could take $4 for McDonald's to figure out a way to do breakfast and burgers together.