Astringency is mouthfeel, not bitterness
Astringency describes the dry, puckering sensation experienced when drinking matcha. It can feel rough or mouth-coating and may linger after swallowing. Bitterness is a taste; astringency is predominantly a tactile perception. They often occur together, which makes them easy to confuse.
Polyphenols interact with salivary proteins and the lubricating film in the mouth. These interactions help explain the sensation, but individual saliva and the food matrix also matter. A single compound concentration does not predict every drinker’s experience.
Which compounds contribute?
Gallated catechins such as EGCG and ECG are relevant to tea astringency. There is no general basis for describing their effect as exponentially stronger than that of other catechins.
A 2025 study combined metabolomic analysis with sensory verification in matcha made from Longjing 43 and Zhongcha 108. It implicated EGCG, quercetin-3-O-glucoside, kaempferol-3-O-rutinoside and kaempferol-3-O-glucoside. Cultivar had a greater influence than processing in that comparison, not necessarily in every matcha.
Cultivation is not a grade guarantee
Shading changed theanine and catechin levels in a separate tea-plant experiment, illustrating how cultivation influences flavor chemistry. It does not justify assuming that culinary matcha comes from sun-grown leaves or that a ceremonial label guarantees the least astringency.
Moderate dryness can be part of a balanced tea. Strong astringency does not by itself prove staleness, poor processing or low grade, and an absence of dryness does not prove artificial processing.
Adjusting preparation without confusing taste and content
If a drink feels too drying, compare a more dilute preparation using the same powder. You can also compare cooler and warmer water while holding the amount of powder constant. Treat this as a taste experiment, not as a proven way to remove compounds or increase health benefits.
Cold matcha remains a suspension of powdered leaf. It is not the same as a cold infusion from which the leaves are discarded: swallowing the powder means retaining compounds that have not dissolved. Cold preparation therefore does not eliminate most astringent compounds, and it does not require the multi-hour extraction schedule of a leaf infusion.
Whisking changes dispersion and texture. The cited research does not establish that crossing 80°C destroys L-theanine or that a precise whisking duration optimizes astringency for every tea.
