McDonald's doesn't actually make their burger patties themselves; they have a number of outside companies that serve as their beef suppliers. McDonald's is the largest purchaser of beef in North America. When beef arrives at a McDonald's restaurant, it is frozen and already formed into patties.
All McDonald's hamburgers are 100 percent beef with an 80/20 lean-to-fat ratio, meaning the burgers contain 20 percent fat before cooking. The beef used in the burgers comes from whole cuts of forequarter and flank meat from the cow. A regular McDonald's hamburger also contains salt, pepper, sour dill pickles, ketchup, mustard and the bun. The top part of the bun is called the crown and the bottom part the heel.
In the Kitchen
The burgers at McDonald's are never flipped. They are grilled on a special electric griddle that cooks the patty from the top and the bottom. This decreases the cooking time: It takes just over 40 seconds to cook the frozen patty. Salt and pepper are added to the burger after cooking. While the patties are cooking, the buns are being toasted on a separate electric griddle. The cook uses a spatula to put the patty on the heel. The condiments and pickles are then added to the top of the patty and the crown is added. The burger is wrapped and slid into a heated serving unit, which the cashier then takes gives to the customer. The total time it takes to prepare a McDonald's hamburger, from the freezer to the customer's hands, is about a minute and a half.