"This "top-secret recipe" is from a McDonalds Manager's Handbook published in 1969. It was meant to be used only as an emergency recipe for stores that ran out of the pre-made sauce that each store used on the Big Macs®. But, this page in the handbook was quickly removed for fear of other burger chains learning and using the top-secret sauce. But, it was too late. The recipe somehow got out and was made public the next year, and has been available ever since. Yields: 1 cup, or enough for 8 burgers..."