Peter Brinkworth, the 81-year-old inventor of chicken salt is probably one of the most iconic Australians.

After discovering the perfect mix of spices and salt to rub on a chook in the 1970s, Mr Brinkworth’s business idea was bought by Mitani in 1979.

Keeping it a secret for more than 40 years, Mr Brinkworth says he still maintains the original recipe which he says tastes even better than anything on supermarket shelves.

His little-known story has now been brought to the screen by Brisbane’s Film Focus Productions filmmakers Jacob Richardson and Thomas van Kalken.

The 10-minute film, Salt of the Earth, will screen at the Adelaide Film Festival on October 20.

After tracking him down through his wife Helen on social media, Mr Richardson said he “had to put this guy on the big screen” after a brief meeting.

Mr Brinkworth described his delicious discovery as a “simple, natural thing” that happened when he was cooking chickens for his retail food store in Adelaide.

“Instead of putting salt and pepper on them, I made up a mixture to just sprinkle with one go instead of using a dozen different containers,” he said.

“It was just out of laziness more than anything.

“There are a hundred recipes out there today and they all reckon they’re good but mine has salt, chicken stock, MSG, paprika, garlic, onion, celery, some herbs and spices.”

And no, there is no curry powder in the original recipe.

Mr Brinkworth said any colour in the salt should be reddish and come from the paprika.