How the Classics Judged a Good Herb from a Poor One

Long before lab analysis, quality was judged by hand: how a root snapped, what color it showed inside, where it grew, how it smelled.

Without chemical assays, classical physicians and gatherers relied on physical, observable tests to judge whether a given specimen was good quality — and the Tangaek-pyeon records several of these tests directly, often as offhandedly as it records taste or nature.

The snap test

Licorice's quality was judged by how it broke: a good root was firm and dense enough that snapping it released a fine powder, which is also where its old alternate name, 'powder herb' (粉草), comes from. Eucommia bark had its own version of this test — quality bark was judged by whether snapping it revealed fine white threads still connecting the two halves, a trait still referenced in herb markets today.

Provenance as a quality marker

Origin mattered as much as appearance. The classics single out specific regions by name as producing superior specimens — goji berries from a particular region were noted for being unusually large, nearly seedless, and exceptionally flavorful, a level of geographic specificity that reads less like folklore and more like an early form of terroir.

Size, color, and freedom from defects

For many entries, simpler visual cues sufficed: whether a root was full and dense rather than hollow or shriveled, whether a fruit's color had developed fully, whether leaves were free of blemishes or thorns. None of these tests required equipment — they required an eye trained by repetition, generation after generation, on the same handful of plants.

Reading old quality tests in a modern light

None of this was quantified the way a modern potency assay would be, and we don't present these historical tests as a substitute for one. What they show instead is a tradition that took sourcing seriously long before modern quality control existed — the same underlying instinct, expressed through the tools available at the time.