Should stems and veins be removed from the raw materials for making matcha?

Yes, stems and veins should be removed.

Reasons:

• Stems and veins contain higher levels of fiber and lignin. If left in, they will result in a gritty and bitter texture in the ground matcha powder, negatively affecting its fineness, flavor, and color.
• During the production of tencha (the raw material for matcha), after steaming and drying, the tea leaves undergo sorting and cutting specifically to remove stems and veins, leaving only the tender leaf parts.
• Tencha processed this way, when ground into matcha, yields a powder with a smoother texture, brighter color, and richer flavor.