In which year was the Coca-Cola formula patented?

The Coca-Cola Company's formula for Coca-Cola syrup, which bottlers combine with carbonated water to create the company's flagship cola soft drink, is a closely guarded trade secret. Company founder Asa Candler initiated the veil of secrecy that surrounds the formula in 1891 as a publicity, marketing, and intellectual property protection strategy. While several recipes, each purporting to be the authentic formula, have been published, the company maintains that the actual formula remains a secret, known only to a very few select (and anonymous) employees.