Here is the story of beer, as told by Tom Robbins — a man dedicated to the playful exercise of free will, ribaldry, and the phantasmagoric — for a young audience. Go on, guffaw; Robbins would approve. Here, as well, is a beer story, one that artfully gnaws upon the truth of that “elixir so gassy with blue-collar cheer, so regal with glints of gold, so titillating with potential mischief.” Those words come from Uncle Moe, radical trickster graybeard relative and guide to Gracie Perkel, kindergartener, who seeks to understand why adults quaff the bitter stuff. The setting is one Robbins knows and draws so well: Seattle, where at 6 p.m. in October the “stars are striking wet matches in an attempt to mark a path through the gloom,” where the constant drizzle erases the fine line between this world and that other, parallel one. Moe takes Gracie to that fine line, then the Beer Fairy — an iconoclastic, dragonfly-size, wisecracking Old Soul straight out of Flatbush — assumes her charge; together they slip through the Seam to the other side, there to mull upon the riddle of beer without parental interference. A brewing lesson follows — barley to malt to mash to wort, add yeast (freelance alchemist) for fermentation (“where the rabbit jumps out of the hat”) — spun with the same pizzazz that Moe laid out beer’s history: “The Egyptians could have invented lemonade — but they chose to invent beer instead.” Trust Robbins’s fairy to sing the joys of beer, a vehicle capable of providing a rapturous peek at the Mystery, the old “hi de ho.” But alcohol is notoriously unreliable transport, he cautions: the mean get meaner, dumb dumber, alcoholism may lurk, drunk driving kills. And if Robbins wraps up this sweet entertainment in too giddyap a fashion, as if he had been dawdling, whereas dawdling is much of the message, thank him for giving kids a life-saving/life-giving beer manual, one they’ll likely actually read.