What astringency means
Astringency in matcha comes from catechins, especially EGCG, which bind to proteins in saliva and produce a drying mouthfeel. Sun-grown, late-harvest, or scorched matcha tends to taste more astringent because catechin levels are higher relative to amino acids. Lower water temperature, finer particle size, and fresher powder all reduce perceived astringency.
Also called
Astringency also appears as bitterness, drying mouthfeel.