This is a re-run from 2015 and from what I can tell, still a secret today. — Dan

In 1952, the owner of a chicken restaurant named Harlan Sanders began franchising out his brand to other restaurateurs throughout the country. Colonel Sanders’ chain, then known as Kentucky Fried Chicken (and now KFC), spread quickly, and Sanders became a very wealthy man. The key to his success: a secret recipe. In 1940, Sanders perfected his “original recipe” of “11 herbs and spices” -- a mix which gave his chicken its distinctive, sought-after taste. Sanders used this recipe as a core part of the franchise agreement; according to Wikipedia, “independent restaurants would pay four (later five) cents on each chicken as a franchise fee, in exchange for Sanders' ‘secret blend of herbs and spices’ and the right to feature his recipe on their menus and use his name and likeness for promotional purposes.”

It would have been easier to simply give the franchisees the herb and spice recipe mix and prohibit its unauthorized use via contracts and patents. But KFC decided not to, believing that the recipe was their biggest point of differentiation. And the recipe remains a secret even today -- in no small part because the company wants to keep it that way.

The secret recipe is hand-written on a piece of paper by Colonel Sanders himself; there are no known copies, digital or otherwise. In 2001, the New York Times reported that the recipe “is locked in a company safe and treated as a closely guarded trade secret. The ingredients are said to be known only to a handful of employees who have signed confidentiality pledges.” And, according to a trade publication, "the executives are prohibited from traveling together due to security reasons.” But most dramatically, even companies that make the spice mix for the chicken giant aren't given the recipe. Instead, KFC gets the spice mix from two different companies: "the mix, distributed to every store on the planet, is made in two parts by two separate US companies and, as a final safeguard, a computer processing system is used to standardize the blending of them to ensure neither has the complete recipe," according to The Times of London.

There’s reason for KFC to take this cloak-and-dagger approach to the recipe -- had Sanders (or, later, the company) patented it, the recipe and process would have been published as part of the patent application. That patent would have eventually expired, allowing anyone to copy it verbatim. And even before the patent expired, the publicly-published description of the ingredients and process could be modified slightly to avoid liability. The only way to protect the recipe, therefore, was via obscurity -- if no one ever knows it, no one can copy it.

It seems impossible to keep such a thing a secret for so long, making many skeptical about the above. There are many who believe that that the entire “secret recipe” protection process isn’t to protect the signature flavor of KFC, but to strengthen the brand’s marketing efforts. The legend of the recipe is always good for a PR bump, as even moving it around it newsworthy. For example, in 2008, according to CNBC, the company “temporarily relocat[ed]” the prized document in order to “revamp security around a yellowing sheet of paper that contains one of the country's most famous corporate secrets.” And as many have pointed out, the "secret recipe" likely changed over the years to account for the mass production of fried chicken required for the company's growth.

So take the secret with a grain of salt -- and with some secret herbs and spices, too.

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Today’s Bonus fact: Colonel Sanders, as he got older, wasn't a fan of KFC. According to the Consumerist, in the 1970s, Sanders commented publicly that KFC's gravy reminded him of "sludge" and the mashed potatoes of "wallpaper paste." KFC ended up suing its founder for libel -- but lost. Why? In part, because, as the court found, "the assertion that the chicken served by Kentucky Fried Chicken Corp. was not prepared exactly according to Sanders' original recipe was not defamatory. It is almost inevitable that at least slight deviations would occur. Indeed, prospective customers would expect that."

From the Archives: Doubting Thomas: How KFC and Wendy's are linked.

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And thanks! — Dan