This cereal grass was known to Greeks, Romans, Chinese, and Egyptians--and was cultivated as early as any grain on earth. Although it had become the chief bread material in Europe by the 16th century, its notoriously low gluten and elasticity made it welcome for filling the belly, but it never brought much joy as a bread or baked in any way.

The decoction of barley water so ridiculed in the Mary Poppins movie was actually a masterstroke of medical wizardry on the part of the ancient Greek doctor Hippocrates. He prescribed it for many ailments, sometimes with the grain, sometimes as a filtered liquid. It's easily made: just boil 2 teaspoons of pearl barley (its other form is hulled barley) in a 5 or so cups of water. When the barley is completely cooked, remove from the heat, let sit a minute, then strain, pressing the solids well.

Perhaps its greatest claim to fame is its transformation into beer, begun by first malting the grains--that is moistening them, letting them sprout, then roasting them.