Short answers, pulled from the story.
Barley was domesticated in the Fertile Crescent around 9,000 BC, with the earliest evidence of cultivated forms coming from the Jarmo region of modern-day Iraq. The earliest known human consumption of wild barley dates to around 23,000 BC at Ohalo II, a site at the southern end of the Sea of Galilee.
World barley production in 2024 reached 142 million tonnes. In 2023, barley ranked fourth among all grains globally at 146 million tonnes, behind maize, rice, and wheat. Russia led production in 2024 with 12% of the total.
In two-row barley, only the central spikelet in each cluster of three is fertile, producing two rows of grain along the ear. In six-row barley, a mutation in the gene vrs1 makes all three spikelets fertile. European brewers traditionally prefer two-row varieties, while North American breweries have historically used six-row barley.
John Barleycorn is a figure from English folklore and a traditional folksong who personifies barley and the alcoholic drinks made from it. In the song, the attacks and indignities John Barleycorn suffers correspond to the stages of barley cultivation such as reaping and malting, and he is ultimately revenged by making men drunk.
Health Canada and the US Food and Drug Administration state that consuming at least 3 grams per day of barley beta-glucan can lower blood cholesterol levels. Whole-grain barley also improves blood sugar regulation after meals, and eating barley-containing breakfast cereals over weeks to months improves both cholesterol and glucose levels.
In Japanese cuisine, barley is mixed with rice and steamed as a dish called mugimeshi. The naval surgeon Takaki Kanehiro introduced barley into institutional cooking in the 19th century to combat beriberi, and it became standard prison fare and a staple of Japan Self-Defense Forces rations.