How Love burns through the Putting in the Seed
On through the watching for that early birth
When, just as the soil tarnishes with weed,
The sturdy seedling with arched body comes
Shouldering its way and shedding the earthcrumbs.
Robert Frost
from "Putting in the Seed"
A little
carbon dioxide, a lot of
water and sunlight, a sprinkle of essential elements--green blades grasp the sky in the late spring.
Still, spring does not last forever. The sun dims, the ground freezes. The exuberant barley of spring has the memory of winters past. It needs to make seed that will survive the winter shadows, seeds that will have enough sunlight stored within to make a new seedling next year, to catch more sunlight.
To understand malt, however, you need know a tiny bit about plants. To know about plants, you must trust that a plant traps sunlight like a whale traps plankton--converting billions of photons, tiny bits of nothing, into something, something that grows and respires and reproduces. Something alive. Whether the whale knows more about the why's than a barley plant I cannot guess, and it really does not matter.
The longs days of summer fuel the conversion of sugar into starches, sugar molecules crocheted into afghans, folded deep within a seed. Solid sunlight.
The seed also holds enzymes, proteins that when activated will start dismantling the starches. When the warmth returns in spring, the frozen ground melts, water seeps into seeds, and they wake up.
Poets and farmers know this already. Peasants know this. Your grandparents knew this. Why not plants?
Malted barley is barley that has been allowed to germinate, thus activating the enzymes that will release the stored sugars and amino acids that will allow the seed to sprout and form the aching seedling. Soon after germination starts, the barley is heated and dried enough to abort the process. Inside the grain, activated enzymes are ready to work as soon as the barley is returned to water.
Brewers mix malted barley with water, yeast, and hops, to create beer.
Malted barley has undergone rigorous biochemical analysis because beer matters. Throw unmalted barley into a pot of boiling water, and you have hot mush. Throw malted barley in hot water, holding it at certain temperatures for a bit of time, and now you are mashing, on your way to making a fine wort, the mother of beer.
If you want to understand mashing, bear with me--a teeny bit of biochemistry follows:
Water activates the stored enzymes, allowing the plant to unravel the starch back into sugars, sugars that hold the energy left from last summer's sun. In the case of barley, most of the restored sugars are maltose, though other sugars are released as well. Proteolytic enzymes break down proteins into amino acids, and diastatic enzymes break down starch. Some diastatic enzymes work on the middle of chains of starch, splitting them in half (alpha-amylase), others work by chopping off the ends of starch into sugars (beta-amylase).
A quick guide to fermentable sugars--the simplest sugar in starch is glucose. Two glucose molecules linked together form maltose, which yeast just love. Three glucose molecules linked together form maltriose, another fermentable sugar. Four or more glucose moecules linked together create a class of carbohydrates called dextrins--yeast cannot consume dextrins.
Yeast loves simple sugars, munching them up, burping up ethanol and carbon dioxide. More complex carbohydrates are ignored by yeast, but give the beer more mouthfeel. By manipulating enzyme activity by mashing the barley soup at different temperatures for varying lengths of time, the master brewer alters the character of the beer.
Yeast also need amino acids to reproduce. Proteolytic enzymes break down proteins into their building blocks, amino acids. Breaking down the proteins also increases the clarity of beer.
Each class of enzymes works best at certain temperatures. High temperatures denature enzymes, rendering them useless.
The master brewer learns how to draw out sugars from his malted barley, break down proteins to feed his yeasties, and to leave enough starch as dextrins to give his brew some character, some mouthfeel. Want a higher alcoholic (and lighter bodied) beer? Hold the wort at a lower temperature for a longer period of time. Want more dextrins? Heat your mash up quickly, preventing the starch from being chopped up too much by the amylase.
(Other factors--pH, thickness of the mash--also change the character of the wort.)
But back to spring, the arching of the seedling towards the sun. Pure energy stored as starch, again released as energy. We interrupt the process. Humans have interrupted the process for hundreds of years, long before we knew enzymes existed. We encourage the yeast to make alcohol, and we drink. Our moods are lifted by the soul of a plant. Spirits.
"The Science Behind the Brew:
The Biology of the Malting and Mashing Processes Used in Brewing Beer," (http://home.comcast.net/~scriptus/brew/brewout-pt2.html)
The New Complete Joy of Home Brewing, Charlie Papazain, 1991