Barley might be the mother of all grains.
Some argue that it was the pursuit of the perfect brew, not food security, that led mankind toward horticulture. And if our ancestors sought to ferment excess grains into potable beverages, there’s no finer accomplice than barley.
Today, many barley varieties are grown across the globe. But two-row barley, Hordeum vulgare, is believed to have evolved from the wild grass Hordeum spontaneum, and was likely one of the earliest crops cultivated by humans.
While sources differ, barley was reportedly first cultivated in the Fertile Crescent 10,000 years ago. It has several advantages as a crop. It’s hearty, resistant to drought and cold weather, its grains are easily stored and transported, and it’s a food source for livestock.
“Barley and emmer were the main grains of ancient Egypt,” says Nigel Tudor, a farmer at Weatherbury Farm near Pittsburgh, which grows ancient grains by historical practices. “And barley was actually the main food source of the Roman legions. When they made polenta, it was with barley, not corn like today.”
But barley’s greatest and arguably most enduring attribute is its association with alcohol production.
Why is barley so important in beer and whiskey production?
Alcohol is created through fermentation, where yeast consumes sugar molecules and excretes alcohol and carbon dioxide as byproducts. Yeasts cling to the skins of grapes and other fruits. So, early humans would have noticed fermentation occurred when they smashed fruits to get the juices.
But coaxing yeast to ferment the longer starch molecules found in grains like wheat, rye or einkorn is complex. That’s where barley comes in.
Each barley grain is a seed that consists of an outer husk, embryo and endosperm. The endosperm takes up most of the mass of the grain, and it serves as the food source for the shoot upon germination. The high levels of enzymes available in the germinating barley seed make the magic happen, and makes it different than other grains.
“It is these food reserves which the brewer needs,” wrote Michael Jackson, beer author and historian, in his book, The World Guide to Beer. “… It is principally the maltose which is later converted by fermentation into alcohol and carbon dioxide, while the dextrins are important in supplying fullness of flavor to the beer.”
When the barley soaks in water, the grain begins to sprout. Two enzymes are released: alpha amylase and beta amylase, also called diastase. These are what the brewer or distiller uses to prep and convert grain before pitching yeast. Otherwise, beer would be a nonalcoholic porridge.
Through a process known as saccharification, the enzymes convert the long starch molecules into smaller maltose molecules and single-molecule monosaccharide sugars, which the yeast can metabolize.
In nature, these enzymes evolved to nurture the budding seedling. There’s a short window to stop the process and preserve the enzymes for brewing purposes, before the young plant consumes the reserves.
Malting halts germination by drying the seeds. It unlocks the enzymes and makes them available to convert complex starch molecules into sugars that yeast can digest. While other grains can be malted, the number of enzymes released when barley is malted is off the charts. It possesses enough of these enzymes to convert starches from other grains included in the brewing process, like wheat, rye, rice and corn.
Today, natural gas or electricity can bake the seeds in large, mechanically turned vats. Traditionally, this was done on malting floors, which were large rooms with a metallic or stone floor that was heated underneath, often by open flame.
Despite being a complex biochemical process, our early ancestors mastered it. Once people figured out how to make “wine” from barley, it was all they could seemingly talk about.
Depictions of people drinking beer appeared in cave paintings. Early Babylonian texts debated the best varieties of barley for different types of beer. And some of the first hieroglyphs from ancient Egypt depicted detailed brewing recipes.
How did ancient brewers unlock this process?
“The malting process is so old,” he said in Still Life with Bottle: Whisky According to Ralph Steadman. “It’s probably a fluke, like everything else. A man was probably storing his barley in a cave, and it was so wet it started to shoot, and he said, ‘I’d better start drying this out and maybe use it.’”