The Australian yeast-extract spread commonly served on breakfast toast is Vegemite.
Vegemite is a dark, salty spread made primarily from leftover brewer’s yeast extract, with vegetable extracts, salt, and flavorings. It is usually spread very thinly on buttered toast because its concentrated savory flavor can be intense. It is also used in sandwiches, pastries, and cooking.
The product was developed in Melbourne by food chemist Cyril Callister and introduced in 1923. Its popularity grew as an Australian alternative to imported yeast spreads, especially during periods when supplies of Marmite were disrupted.
Vegemite and Marmite are related but distinct brands with different recipes and flavor profiles. Vegemite is strongly associated with Australian food culture, while Marmite originated in Britain. Neither spread is a fruit jam; both are savory yeast-extract products.