The Difference Between Burger King And McDonald's Beef
Burgers from McDonald's and Burger King don't taste the same, but that has nothing to do with where the companies get beef. Both restaurants use the same primary beef supplier, Lopez Farms, and both chains make patties in centralized locations before shipping (typically) frozen burgers to restaurants. The differences come down to how they are cooked.
At McDonald's, frozen patties (and the fresh-never-frozen Quarter Pounder) are cooked in a clamshell grill that resembles a long, giant panini press. Whether it's a few seconds for fresh or a few minutes for frozen, the lid automatically releases when done, and an employee then adds salt and removes them with a spatula. At Burger King, the process is even more automated.
Burger King markets its burgers as flame-broiled, and they actually are. Frozen patties are loaded into a commercial-grade upright broiler for a few minutes and deposited via a conveyor belt to a holding tray when done. Sometimes, reflections of the flames inside can be seen on the loading or holding trays. These flames also put Burger King a cut above some of the competition: while some fast food restaurants use fake grill marks on burgers, they're said to be a real outcome of the broilers (McDonald's burgers do not have any grill marks, real or fake).
When McDonald's and Burger King deviate from their processes
These two fast food giants have such exacting processes for cooking burgers in order to maximize efficiency, but there are exceptions to the rules, and they largely revolve around satisfying customer requests. For example, Burger King will cook you a fresh Whopper if it's ordered "hot off the broiler." But savvy ad watchers might be wondering: aren't all Whoppers made fresh?
It is Burger King policy that all Whoppers be made to order, but some franchisees take liberties with the spirit of that by assembling the sandwiches to order, using Whopper patties cooked some time ago and held in a warmer. Using that phrase may disrupt the usual process at such Burger Kings, but it's an important enough customer request that it's an option in the Burger King app itself.
McDonald's also has a way to get a freshly cooked burger, and it also requires a deviation from the usual process. Requesting a burger with no salt requires them to make a fresh one, as every patty in the warming tray had salt added as a matter of course. Or, if you don't want to seem like you're trying to pull a fast one on an employee who's probably seen it all, you could simply request a freshly cooked burger — though asking for it unseasoned leaves them no choice.