Hi, I'm Ben. I'm a senior lecturer and
researcher in the School of Chemistry
and Molecular Biosciences at the
University of Queensland and today we're
going to do a little experiment on how you
can make beer, or something similar to beer
anyway, out of Vegemite. So yeast is
a wonderful little microorganism that
can turn sugar into alcohol and it can do
that reasonably well, but to be able to
grow yeast needs more than just sugar. It
needs some other nutrients and Vegemite
is a yeast extract and it's actually a
really good source of those other
nutrients that yeast needs to be able to
grow.  So, to make an efficient
fermentation we need all three of these
ingredients: sugar, the Vegemite and the
yeast itself. So, to make a Vegemite beer
will take a bit of sugar to start with.
And then dissolve that in some warm water.
And then the other ingredient which we
need is a little bit of Vegemite. Now, we
actually don't need much Vegemite at all
in here to allow the yeast to grow and
the more we put in, the stronger or the
darker this solution will turn and also
the more Vegemite flavours will be
present. So, for some who like Vegemite
that might be a good thing others, might
not be so sure but we'll put in a good
healthy teaspoon for the moment. Now,
this Vegemite is not as soluble as the
sugar and so you might be able to see
there it's sort of clumping up a little but
if we mix it around then eventually that
will dissolve quite nicely.
So there's still a little bit of residue in
there but it's nicely dissolved and
we've got a quite sort of murky,
interesting coloured concoction here. Now,
this solution as it is would be great to
go, if we were to add yeast to that then
the yeast would grow happily and would
ferment the sugar into alcohol, it might
take a couple of days for that to happen.
But this [sniffs] it smells quite interesting.
There's a whole lot of Vegemite-y
flavours in there, that's probably the best way
to describe that. Te sort of earthy, meaty,
quite pungent flavours. And some people
might like that but others might not
find it so tasty. And a really good way
of removing those flavours is by heating,
boiling or simmering this solution, and
so what we'll do now is to take half of
this ... Vegemite work or pre concoction
and boil half of it to get rid of those
flavours.
So I'll put that on our heating block there ...
and let that boil.
Okay, so now this has come to the boil,
it's simmering away nicely there and ... it's
giving off some lovely sort of burnt
caramely smells and Vegemite flavour as
well so ... actually it doesn't smell to bad.
And if we let that simmer now for half
an hour or so, then most of those
volatile Vegemite flavours will all
dissipate and go away, and we cool it
down then those flavours won't be present
in the final Vegemite beer. Now, at this
stage if you want to you can add some
other things for exciting flavours, so
like ginger for a ginger beer type thing,
or even hops for something that's a
little closer to normal beer or
whatever else exciting and flavoursome
might take your fancy. So we'll just now
let that simmer for half an hour or so
until it's done.
Okay, so now this Vegemite sugar mixture
that we have boiled is now cooled back
down to room temperature and actually, it
actually smells quite nice. It's sort of
got a light Vegemitey-ness there but  ... it smells
quite sweet and caramely as well, not
too unpleasant. And this one on the other
hand was again Vegemite and sugar but
it's just been left at room temperature
for about half an hour and it smells
really, really strongly a Vegemite which
again some people might like but is
pretty powering, overpowering. So at this
stage now that these are both cool we
can add yeast, now we had to make sure
this was cool because otherwise the
yeast would have been killed by the high
temperature but now it's cool the yeast
will be happy. So, now we're going to add
some dry yeast into these. So, we'll just
use ordinary bakers  yeast for this and
that will work - the yeast will be able to
cement the sugar into ethanol. If you
were making this for ... something that
was like beer, then you could use any
sort of brewing yeast you wanted to
and different brewing yeasts can give
different flavour characteristics to the
beers that they make. But today we'll
just add a little bit of this yeast. So just a
small little half teaspoon into each of
those. And then just a quick mix, to mix
around that yeast.
So now we could leave these and that
fermentation would begin. So here these
will begin to bubble in a couple of
minutes and the yeast will ferment the sugar
into ethanol over a day or so, but if I
was making this at home in a slightly
larger scale I would use a large plastic
fermenter, the sort that you can get
from any home brew shop.
Okay so that's pretty much all there is
to this experiment but these will take a
couple of days to ferment into a
finished product. So instead we can take
a couple that I prepared earlier - one
with the cold preparation and the other
with a simmered preparation so how about we
head out to the Great Court and see if
we can find anyone who's brave enough to
try these different Vegemite beers. Okay,
so we're here near the Great Court and we've
found Michael who's willing to try some
of our Vegemite beer, so let's serve
some up! Yeah, you're very brave. Good.
Oooof!
Cheers!
Oooh, it's very smooth, well done.
