The recipe is actually known. I came across a long article on the web about it. The true secret was that he used pressure cookers in the early years that no one else did.

Here's what Bing AI found and it might be from the article I read:

Here is an article I found on the KFC secret recipe. According to Joe Ledington, Colonel Sanders' nephew, the recipe consists of the following 11 herbs and spices: 2/3 tablespoon salt, 3 tablespoons white pepper, 1/2 tablespoon thyme, 1/2 tablespoon basil, 1/3 tablespoon oregano, 1 tablespoon celery salt, 1 tablespoon dried mustard, 4 tablespoons paprika, 1 tablespoon garlic salt and 1 tablespoon ground ginger¹.

The recipe is one of the most valuable fast food formulas and is considered one of the biggest trade secrets in the world³. The original handwritten recipe is housed in a 770-pound safe encased in two feet of concrete and guarded by video cameras and motion detectors³.

Source: Conversation with Bing, 6/23/2023 (1) What is the KFC secret recipe? Top 11 herbs and spices 'revealed'. https://twistedfood.co.uk/articles/features/kfc-secret-recipe-colonel-herbs-spices. (2) Is This the Top-Secret KFC Recipe? - The New York Times. https://www.nytimes.com/2016/08/26/dining/is-this-the-top-secret-kfc-recipe.html. (3) KFC Original Recipe - Wikipedia. https://en.wikipedia.org/wiki/KFC_Original_Recipe. (4) Here's KFC's Secret Recipe to Extra Crispy Fried Chicken - Taste of Home. https://www.tasteofhome.com/article/kfcs-secret-recipe-crispy-fried-chicken/. (5) What Are KFC's 11 Herbs and Spices? - Allrecipes. https://www.allrecipes.com/article/what-are-kfcs-11-herbs-and-spices/.

The whole super guarded recipe part I believe to be pure marketing pablum, a ruse to generate conversation.

i think it’s more about branding than actual secrets. chances are it isn’t that remarkable but it makes it fun for customers to talk about it as a mystery.

It's literally on Wikipedia - https://en.m.wikipedia.org/wiki/KFC_Original_Recipe

This is the one I use, previously found on the site-which-shall-not-be-named.

My favourite history. Pat Grace's Famous Fried Chicken: https://open.spotify.com/episode/0uFbJFPRxd7Or4EiJ1V0jy

Because it’s a secret?

It's not really that good anyway imo. Sure it's good, but it's fried chicken, and our mom's simple recipes are probably way better.

I wonder if it's like a No 2 pencil, where no single individual is capable of building one on their own. The skills, materials, and machinery are spread across numerous entities.