Comment by Mountain_Skies

Pepsi probably also has had access to Coke's supply chain and long ago acquired samples of various inputs before mixing, which would make analysis easier. The two companies know they're competing mostly on production management and brand image, not secret ingredients. A decade or so ago a secretary from Coke tried to sell some of the company's "secrets" to Pepsi. Instead of jumping on the opportunity to get Coke's secrets, they contacted Coke's legal department and the FBI, with the three working together to prosecute her.