How It’s Made
Spent brewer’s yeast is strained to get rid of hop resins, and washed to remove bitter tastes. Then it is suspended in water at a temperature greater than 37 C with no nutrients. The yeast cells die, and vitamins and minerals leach out. Then the proteolytic (protein-splitting) enzymes take over, breaking the yeast proteins down into smaller water-soluble fragments. These also leach out, a process called autolysis. The yeast cell membrane is unruptured during this time, and can be removed by centrifuging. The clear light brown liquid is then concentrated under a vacuum to a thick paste (the vacuum helps preserve flavours and vitamin B1, thiamine). It is seasoned with salt, and a small proportion of celery and onion extracts to increase palatability.
How to make Vegemite
- Find out how long it takes yeast to die, and then once they have how long does it take before autolysis to be complete.
- Make beer and keep the spent brewers yeast.
- Using a sieve strain the brewers yeast, wash it.
- Suspend yeast in water at 40⁰ until the yeast cell destroy themselves.
- Remove the cell membranes using a centrifuge.
- Concentrate the remaining liquid under vacuum.
- Add salt, celery extract, and onion extract.
- Mix it all together.
- Make toast.
- Butter toast.
- Spread Vegemite onto buttered toast. Not too much.
A Brief Hostory
Vegemite dates back to 1922 when the Fred Walker Company hired a Dr. Callister to develop a spread to replace Marmite, a thick past made from spent brewer’s yeast.
Brewer’s yeast is a good source of vitamin B, but it is poorly digested. Making yeast extract using autolysis: a process where the yeast’s own enzymes break it down, makes it more digestible. Yeast extract, contains a high concentration of glutamic acid, which is the source of Vegemite’s rich umami flavour. Vegemite does not contain any fat, added sugar or animal content.
Vegemite is so rich in vitamin B that that in 1939 Vegemite was officially endorsed by the British Medical Association. During World War II, Vegemite was included in Australian Army rations.