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The world's best-hidden secret recipes


As the Summer of Secrets arrives on Sky HISTORY we’ve put together a series of articles to flavour this exciting season of programming. Some of our favourite meals include ingredients we could never replicate at home. Whether it’s the immediately distinct flavour of Worcestershire Sauce in your cottage pie or the instant fizz and taste that comes with a glass of authentic Coca-Cola, there’s mystery in those recipes the creators simply won’t share.

Let’s look more closely at some of the world’s most famous secret recipes and the intrigue surrounding them.


The original recipe of Coca-Cola remains one of the world’s best-kept secrets. It was invented in 1886 by a pharmacist from Atlanta called John Pemberton. The recipe was then purchased by Asa Griggs Candler for £1,800 at some point between 1888 and 1891. Candler used his nouse and realised just how much money the formula could make, and turned it into a reputable business.

Coca-Cola remains the world’s most popular soft drink and the secret recipe is still simply a handwritten formula on a piece of paper. Not content with just keeping it under lock and key, the company holds the recipe in a secure vault in Atlanta.

Huy Fong Sriracha

Legend has it that one of the world’s most famous hot sauces was first created by Ms. Thanom Chakkapak in a small town called Si Racha in Thailand. However, Vietnamese national David Tran was the first person to begin bottling the sauce under a brand name in the US. He is noted as the person who made the sauce famous.

Unlike Coca-Cola, it isn’t the recipe itself that is secret here, but the machinery Tran has modified himself. Working with the Huy Fong Food company, Tran created a unique production process. With his specialised machinery, no one else can recreate the exact flavour of his trademark Huy Fong Sriracha.


KFC is one of the most recognisable fast-food brands and flavours on the planet. The company is worth over $10 billion and this is all down to the unmistakable and unique flavour of its chicken. The original formula was first worked on by Colonel Sanders in the 1940s and is a very highly guarded secret to this day. Only two KFC executives know every herb and spice used in the unique formula.

The recipe itself is in a hidden location with two-foot thick walls, security guards, and round-the-clock surveillance in place. There are two unique pin codes held by those same two executives who can only open the vault with a combination of these codes. Newspaper reports suggested the secret recipe may be revealed in 2017, as a journalist claimed to have discovered it in a Sanders family scrapbook, but the company quickly refuted this claim.

Lea & Perrins Worcestershire Sauce

Authentic Worcestershire Sauce adds a real kick to any meal, whether that’s an extravagant dish or a simple slice of cheese on toast. Essential for meats and marinades this umami-like sauce has all its ingredients listed right on the back of the bottle, but the precise mix is missing.

The exact combination of ingredients is a closely guarded secret and something the company is very proud of. The original recipe was invented by a pair of chemists under the command of Lord Sandys, a nobleman who wanted to bring the rich flavours of India to his English dinner table.


Certainly an acquired taste, the French herbal liqueur Chartreuse remains a closely guarded secret. The recipe is kept by the Carthusian Monks and has been made to the same instructions provided by François Annibal d'Estrées in 1605. Chartreuse has two distinct flavours, one in green and one in yellow, and both have different alcohol contents too.

Green Chartreuse and Yellow Chartreuse both offer a unique floral and herbal flavour and the formula for each product is unique and a hidden secret held by the monks and no one else. Many people have attempted to replicate the flavours of Chartreuse but no one has ever come close.