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barton cole :: veni, vedi, vero scripsi
 Saturday, January 10, 2009
Let's represent a sugar molecule like this:
X
Although there are many different kinds of sugar (glucose, sucrose, fructose…), we'll keep it simple.
Take a little leap, though, and think of the molecule as C6H12O6 (six carbon molecules, twelve hydrogens, six oxygens - put together like building blocks).
String a bunch of sugars together, and you have a starch (just a long chain of sugar molecules):
XXXXXXXXXXXXXXXXXXXXXXXX
A much longer chain of them gets you cellulose, which is wood fiber:
XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX
Starch is an excellent way to store sugars for energy, which is why grains are starchy - they need that sugar to get the sprout up and out of the ground; the plant needs an energy supply until it can get some leaves photosynthesizing and making its own energy.
To break the starch down into sugars, you need enzymes - they take the chain apart.
The enzymes that take sugars apart are called amylases; enzymes that deconstruct proteins are called proteases, and fat-breaking enzymes are lipases…
There are two principle amylase enzymes: the alpha and the beta. The alpha assesses the starch molecule, finds the middle, and cuts it there, like this:
XXXXXXXXXXXXXXXXXXXXXXXXXX becomes
XXXXXXXXXXXXX XXXXXXXXXXXXX
It keeps doing it, too - it will take those two halves and halve them again.
The beta enzyme works from the end of the starch molecule, taking off two glucose molecules at a time, like this:
XXXXXXXXXXXXXXXXXXXXXXXX
becomes
XXXXXXXXXX XX XX XX XX XX XX XX
Barley is loaded with these enzymes, much more so than any other grain, an attribute we can exploit, as we'll see.
But it doesn't serve barley for the enzymes to convert its own starches to sugars until it needs them, so it has a meager supply, basically, until the seed gets "switched on," and its time to utilize that efficiently-stored energy (the starch molecule takes up far less room than the sugar molecules it's composed of, since it's kind of like a neat coil inside the grain, a tightly-packed chain).
How do you switch the seed on?
You sprout it.
In the case of barley, you soak it in water until it germinates, and the little, ambitious "acrospire" (the sprout) emerges.
When the acrospire is about ¾ as long as the grain, the enzyme count increases dramatically, much longer, and the enzymes will begin digesting the starches in earnest, but you want to hold off a bit…
So you switch the seed off. How?
You dry it out, so the acrospire withers, and that's that.
The barley you began with has now been "malted," and you now have "malted barley." That's all there is to it.
Beer is made from malted barley. How do you do that?
Beer is a fermented beverage, which means that the sugars have been converted to alcohol by yeast, which are simple organisms. Yeast digests sugar (just like we all do, fundamentally), excreting alcohol (C2H5OH) and carbon dioxide (CO2).
If you're into it, do the balance sheet -
Sugar: 6 C 12 H 6 O
Alcohol: 2C 6H 1O
Carbon dioxide: 1C 2O
If you balance it out, you see that one sugar molecule generates two alcohol molecules, and two carbon dioxide molecules, nothing left over.
(For extra credit, ponder how plants use CO2 and water [H2O] to make sugars, including chains of starches, and obviously, cellulose [plant fiber, remember?]).
Looks like making alcohol is going to be pretty easy - start with malted barley, get some yeast…
You've got to make conditions favorable for the enzymes in the barley to convert the starches to sugars; turns out that the ideal conditions are wet heat - around 150°.
First, though, you have to render the grains into a form that makes it as easy as possible for the enzymes to get at the starches, so it gets crushed by passing it between rollers.
If you add water that's hotter than 150°, and plan it out ahead of time so you start with water of the right temperature, once you add it to the crushed, malted barley, the temperature settles into the favorable range. Of course, it's also possible to apply heat to the wet, crushed grains to get the temperature into the zone.
This is called a "mash."
I always wanted to know what one was; see rapid research.
And the enzymes get busy - soon, they have converted all the starches into sugars, which is easy to verify: pull out a spoonful of the grains and drop some iodine into them - from chemistry class years ago, you may recall that iodine, which is red, turns black when it contacts starch - one simply tests for the presence of starch until it isn't present any more, maintaining the temperature of the mash in the favorable range.
Now, you have a mass of wet, crushed, malted barley that is now sweet - all the starches have been converted. Bootleggers go this far and add yeast, fermenting it until the yeast activity ceases, once the yeasts have converted all the sugars into alcohol and carbon dioxide. Then they distill it (a topic for another day, but a dear one, to me).
Brewers, though, start the same way, but have to get the sugars out of the grains - who wants porridge in their beer?
Usually, they'll put the mash in a pot that has a screen bottom, and wash the sugars out of the grains with hot water, collecting the water and putting it in a pot.
This is called "wort," and once it's boiled with hops (a perennial vine with bitter flowers growing in clusters like grapes), it can be fermented and will have become beer (sake, generally called "rice wine," having been made from grain is actually "rice beer").
Pretty straightforward stuff, really. Beer has been around for over four thousand years, having been invented in Mesopotamia.
How would someone know what to do to the grain to make beer out of it, though?
It was either advice from the alien overlords who seeded the earth with people and ideas, or it happened accidentally, which is easy to imagine:
Let's say you have a sack of grain, and it rains. The grain sprouts.
But you want to eat it, not plant it, so you try to rescue it by drying it out.
Darn it, though! It gets wet again, but this time, you don't catch it until it's been there for a couple of weeks, the grains floating around, and now yeast has gotten at it - which is common, there being so many yeasts drifting around.
It's really ruined now, but not wanting to throw it out, you eat some of the grains, and discover alcohol in the process.
For extreme extra credit, consider this:
Agriculture began in the Fertile Crescent, around the Middle East. Grains were grown, stored, and marauded by rats.
Cats to the rescue!
This is when cats became our companions - by protecting the grains by hunting the rodents who were eating and spoiling it.
What if cats hadn't come on the scene?
Rats would have had their way with the silos of grain, and people would likely have given up growing grains.
"Forget this agriculture thing," the early, pissed-off people might have said.
"Let's go back to hunting/gathering."
Without cats, we might have abandoned agriculture, and that would certainly have meant no beer!
So we have cats to thank for beer getting off the ground in the first place.
The next time you have a beer, raise your glass to the cat and shout its name.
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