KFC disclosed a "7-10-7" breading process in which each chicken piece is rolled seven times, tossed in flour 10 times and pressed seven times before frying.
The chain said Colonel Harland Sanders also designed a precise clamshell-basket racking layout so pieces do not overlap, helping breasts, drumsticks and other cuts cook evenly together.
KFC still uses commercial pressure fryers pioneered by Sanders in the 1940s, a method the company says creates a crisp crust while keeping the meat juicy.
The disclosure opens part of a famously guarded system built around Sanders' 11 herbs and spices recipe, which KFC says remains locked away and blended through a split-supplier process.
Founded on its first franchise in Utah in 1952, KFC has expanded to more than 31,000 restaurants across 150 countries and territories.