Traditional kratom use involved brewing and smelling the plant to assess concentration.

“Historically or what you call the traditional use. People would harvest the plant. They have knowledge of kind of the the coloration of the plant, the texture of the field. A lot of unconscious knowledge too. Um maybe it's passed down through generations. Maybe they just learn it, you know, in a couple of years and next thing you know they're brewing it, they're drinking it. As they're brewing it, they're smelling it. There are many more um avenues of information coming in about the concentration.”