Vegemite's Port Melbourne factory in 1957.
Vegemite turns 90 this month. Like Holden Cars, Aeroplane Jelly and Chiko Rolls, Vegemite is one of our greatest and most iconic brands. Sold as a healthy spread to smear on our toast, its 1950s radio advertising jingle We're Happy Little Vegemites was absorbed into our national vernacular.
It was championed as our globally recognised dish in Men At Work's 1981 song Down Under in which Colin Hay sang, ''Buying bread from a man in Brussels/He was six foot four and full of muscle/ I said, 'Do you speak my language?'/He just smiled and gave me a Vegemite sandwich.''
And like Holden cars, Aeroplane Jelly and Chiko Rolls, Vegemite is American. It is owned by Kraft Australia, itself a wholly owned subsidiary of Mondelez, where it sits alongside brands such as Toblerone, Philadelphia Cream Cheese and Oreos.
The Vegemite recipe was developed by a food chemist called Cyril Callister at Fred Walker's eponymous cheese factory in Albert Park. Walker, a former Caulfield Grammarian, was in debt to the tune of £80,000 from a previous company and was developing new food lines to push himself back in the black.
Vegemite was not a new concept. The process of extracting the nutritious insides of yeast cells had been developed in Germany in the previous century. Vegemite was the local answer to England's Marmite, a yeast extract first produced in 1902 in Burton on Trent. Marmite used post-ferment brewer's yeast from the nearby Bass Brewery, thus solving the problem of what to do with spent yeast.
The food culture of creating concentrated nutritious extracts packed in tins and jars extended even further back to the Franco Prussian War, when Scottish-born Canadian John Lawson Johnston developed ''Johnston's Fluid Beef'' to feed Napoleon III's Army. It was later renamed Bovril.
Callister's version of a yeast extract was developed in 1923 with marketing beginning the following year, the name Vegemite supposedly chosen at random from competition entries pulled from a hat by Walker's daughters. The winners were local Albert Park girls whose entry mirrored the marketing phrase on the first amber-coloured jars ''Pure Vegetable Extract'' and ''delicious on sandwiches and toast. Improves the flavour of soups, stews and gravies''.
In 1926 Walker formed a new company with James L. Kraft of Chicago to process cheese called The Kraft Walker Cheese Co. By 1930 manufacturing for both companies was consolidated and when Walker died of hypertensive heart disease in 1935 the Australian holdings of the company were absorbed by Kraft in Chicago.
The Vegemite plant is now in Salmon Street, Port Melbourne. You may have never seen it, but you surely would have smelt it. Vegemite is made from post-ferment brewer's yeast trucked in from breweries around Melbourne and, during processing of the yeast, releases a sweet bakery-like aroma into the air. The yeast is treated with plant enzymes to break down its cell walls to leave basically a lot of protein, B vitamins and amino acids that are cooked with salts and natural vegetable flavours. For several hours after, the ''black velvet'' is extruded warm into jars and sealed. More than 25 million jars are produced annually, with 95 per cent sold in Australia and New Zealand.
Vegemite's appeal is deep-rooted in our brains. Its saltiness pleases our ancient and instinctive desire for salt while the amino acids give an enticing mouth-filling sense of savouriness, a sensation the Japanese refer to as ''umami''. In global gastronomic circles, Vegemite is recognised as Australia's source of umami alongside Germany's sauerkraut, Italy's parmesan cheese, Malaysia's belachan, Thailand's fish sauce and Spain's anchovies. All can be acquired tastes.
And it is because Vegemite is an acquired taste that we are so fond of it and so defensive of it. As Australians we take great delight in watching the facial reactions of people from other cultures when they taste Vegemite for the first time. The question ''Have you tasted Vegemite?'' has replaced ''What do you think of Australia?'' in celebrity interviews.
In 2006 Australian officials investigated reports that the US Food and Drug Administration had banned sales of Vegemite because of its levels of folate, an additive regulated in the US. The Australian Embassy was aware of reports that people were being stopped from bringing the breakfast spread into the US. The story later turned out to be based on rumour.
Trans-Pacific relations were further tested in 2011 when then Prime Minister Julia Gillard was in a school in the US meeting President Obama. She was asked by a student: ''What is Vegemite?'' and replied: ''Right. This is a bit of a difference between the President and I. I love Vegemite.'' Obama replied, with a laugh: ''It's horrible! … it's like a quasi-vegetable byproduct paste that you smear on your toast for breakfast. Sounds good, doesn't it?'' The reason we love Vegemite is because others hate it. It helps define who we are. Happy birthday, Vegemite.