VEGEMITE is a household staple; it's become almost a synonym for Australia and was trumpeted to the world in Men at Work's exuberant song Down Under.
The Kraft plant in Port Melbourne produces 23 million jars yearly. But for its first 15 years, the mucky brown breakfast paste we love was shunned, and one man kept it from oblivion.
This was its scientist creator, Cyril Callister, whose life story has been documented in a new book, The Man Who Invented Vegemite.
The author, Cyril's grandson Jamie Callister, says the man behind our national breakfast spread deserves ''to be remembered as a significant and remarkable Australian''.
This is the first book for Callister, a builder and former advertising executive who lives on the Gold Coast. But after reading through a trunk of Cyril's letters and documents he felt it was ''destiny'' to tell the story.
Cyril's father, William Callister, was principal of a tiny school at Chute, west of Ballarat, where Cyril was born in 1893.
Cyril won a scholarship to study science at the University of Melbourne, and during World War I, was recruited to make explosives at a top-secret industrial complex in Scotland.
Cyril met his future wife, Kit, there, and after the war brought her back to Melbourne.
Two of their children would contract polio, and the third, Ian, became a World War II fighter pilot who died in the Pacific when an Allied aeroplane ploughed into his.
From the early 1920s, with imports of the British yeast extract Marmite having been disrupted by World War I, Melbourne food entrepreneur Fred Walker set Cyril Callister up in a lab to find a home-grown alternative.
The name Vegemite was pulled out of a hat by Walker's daughter Sheila and ingredients were sourced from local breweries.
Three years after Vegemite's 1923 release, the public was rejecting it and Walker tried to change the name to Parwill.
The name was a sly dig at Marmite, with the slogan ''Marmite, but Parwill'' (as in Ma might, but Pa will).
The name Vegemite won out, although the spread remained unpopular.
But Cyril, now a director of Fred Walker & Co, ensured it kept being produced, and the licence Walker secured with US giant Kraft to produce processed cheese diverted the pressure for Vegemite to succeed.
Jamie says Cyril had ''an unshakeable belief in Vegemite, that it was good, and he persevered''.
Then, a stroke of luck.
Vegemite was added to World War II soldiers' ration packs and it became a quirky patriotic symbol. Medical confirmation of Vegemite's rich B1 vitamin content had come in 1938 and prompted aggressive health-related advertising.
One early ad claims Vegemite could cure everything from constipation to jumpy nerves.
Cyril died from a heart attack in 1949. Jamie, 52, never knew him, but before Jamie's father, Bill, died in 2001, he urged Jamie to carry on the family story.
Jamie doesn't get any Vegemite royalties and the book isn't connected to Kraft.
He just wanted to honour his grandfather's life. ''It's my story but it's our story because we've all grown up with it, anyone who's had Vegemite on the table,'' Jamie says.
The Man Who Invented Vegemite, published by Murdoch Books, will be launched at a community hall in Beaufort near Cyril's birthplace on October 11 at 11am, followed by Vegemite sandwiches.