Love it or loathe it, Vegemite is one of Australia’s most iconic products. It was first manufactured in 1922 by Cyril P. Callister in Melbourne from yeast left over after beer brewing, but can it be used to make beer?
The key ingredients in beer are malted barley, hops, water and yeast. The sugars and nutrients released from the barley are used as food by the yeast, which ferments the sugars into ethanol and carbon dioxide, providing the alcohol and bubbles for beer. The barley can contribute flavour characters through different varieties or roasting, while the hops add a pleasant bitterness and protect the beer from infection.
Because yeast grows during fermentation, a large amount of spent yeast is produced for every batch of beer made. Vegemite is a food spread made from this leftover yeast. After collecting the spent yeast sludge, the yeast cells are broken open by the addition of salt and heat. No yeast should be able to survive this process, making it very unlikely Vegemite could be used as a source of yeast in beer brewing.
Nonetheless, in recent years Vegemite has been reportedly used in prisons and dry communities as an ingredient in illicit homebrew. Is this possible?
We set out to investigate. We first found that there was no living yeast in Vegemite. Instead, we found that Vegemite provides many of the nutrients needed for yeast...
