Well, rhubarb is a bit odd. The rhubarb we eat is the stringy, almost inedibly acidic leaf stalk of an Asian weed. Yet we know it best as a sweet fruit component that tastes of saccharine Americana.
(Even if we too often neglect rhubarb, leaving it stifled under strawberry’s oppressive thumb. To patronize rhubarb as it “pie plant” demeans it, not-too-subtly suggesting it is good for no more than being cloaked in strawberry syrup.)
Oh, and rhubarb seems to be one of the few palatable things to have survived last summer’s heat and this dank cold spring in the Upper Midwest. And “local” and “seasonal” is a thing.
Maybe because rhubarb is so seasonally scarce, along with being chemically weird and coyly nostalgic, it has recently caught the eye of molecular gastronomy. Although no one ever admits to a craving for it, rhubarb has shown up on the menus of at least half of the worlds’ top ten restaurants in the last couple of years
Originally from Central Asia, rhubarb became known in the West when Silk Road traders plied its root to Europeans as a medicinal purgative. In the Eighteenth Century, rhubarb stalks first came into culinary use in France, helped along, one expects, by the new availability of sugar.
Rhubarb is also somewhat toxic. And to taste anything that needs to bear a warning gives us a little flavor of the rush children get from daring to eat a spoonful of cinnamon.
Rhubarb contains oxalic acid. Oxalic acid binds to calcium in the body, then crystallizes in the kidneys where it can cause kidney stones and worse. The level of oxalic acid in the stalks is not all that much more than in, say, spinach, so they are fine.But don’t eat the leaves. They contain way too much oxalic acid.
Really, don’t eat the leaves.