But what exactly is Vegemite?
The popular dark brown spread is the invention of Dr. Cyril P. Callister, a chemist at Australian company Fred Walker & Co.
Following the disruption of imports of the British food spread Marmite after World War I, Fred Walker & Co. asked Callister to develop a spread from the used yeast dumped by breweries.
Callister blended the yeast extract with celery, onions and a mix of spices to create a paste similar to Marmite, and the food spread was unveiled in 1922.
The dark, sticky substance was described as salty, malty and slightly bitter.
A nationwide competition to name the spread ended with the selection of "Vegemite," and in 1923 the product began to appear in ads, emphasizing the value of the food to children's health.
Vegemite's sales were dismal though, and facing growing competition from Marmite, the product was renamed "Parwill" in 1928.
The new name was selected to make use of the slogan "Marmite but Parwill," a parental pun that poked fun at its competitor. (As in "If Ma might, then Pa will.")
However, the marketing campaign was unsuccessful, and the spread was renamed Vegemite in 1935.
Ten years previously, Fred Walker had formed a joint company with J.L. Kraft & Bros., which is today known as Kraft Foods. Walker had the idea to use the success of Kraft cheese to help Vegemite sell, so the salty spread was given away with the purchase of cheese products.
The two-year campaign was a success. During World War II, Vegemite was included in Australian Army rations, and by the 1940s, the spread was used in nine out of 10 Australian homes.
Today, Vegemite outsells Marmite and other similar spreads in the Land Down Under, but the 90-year-old brand is working hard to win over the taste buds of a new generation of Aussies.
It's an especially hard sell for many foreign palates, although the domestic popularity of Vegemite still inspires a lot of non-Australians to try it, often with amusing results. Some Americans, for example, have posted taste-test videos on social media — sometimes just eating a spoonful straight instead of using it as a spread:
(It's worth noting this is not how Vegemite is typically eaten in Australia, where it's often spread lightly on buttered toast or incorporated into a sandwich.)
And in the video below, you can see a group of Danish schoolchildren try Vegemite for the first time. The boy at the one-minute mark looks to be the only true fan of what's been hailed as "Australia's national food."
Photo: Ian Waldie/Getty Images
Editor's note: This story has been updated since it was originally published in April 2014.