The four enemies
AIR oxidises aromatics and flattens tea over months. LIGHT degrades chlorophyll and accelerates staling, which is why the attractive glass jar on a sunny shelf is the worst common storage there is. MOISTURE lets mould establish and ruins the leaf outright. ODOUR is the one people underestimate: dry tea leaf is highly absorbent and will take on the character of a spice rack, a coffee tin or a cupboard within weeks.
What good storage looks like
Opaque, airtight, at stable room temperature, away from the cooker and anything aromatic. A tin with a well-fitting double lid is as good as anything expensive. The original foil pouch, folded over and clipped, beats a decorative ceramic jar that does not seal. Do not refrigerate ordinary tea — the temperature swing on removal causes condensation, and the leaf will absorb whatever is in the fridge.
The exception that matters
Dark tea inverts the first rule. Raw pu-erh has to breathe, because the microbial activity that ages it needs air; sealing it airtight arrests the process it was bought for. Unglazed clay jars, cardboard boxes and ventilated cupboards are all appropriate, and a sealed bag is the one thing to avoid. Ripe pu-erh is less sensitive but follows the same principle.
How long things actually keep
Japanese green tea is at its best within a few months and is genuinely worth refrigerating unopened, then bringing to room temperature before opening. Chinese green tea is similar. Oolong keeps a year or more, roasted styles longer. Black tea keeps a couple of years and slowly dulls. Matcha oxidises fastest of all once opened — weeks rather than months — which is the most expensive fact in this guide.
The mistake nobody warns about
Washing a storage tin between teas. It seems obviously right and it is wrong: a washed tin holds residual moisture, which does more harm than a trace of the previous tea’s aroma. Wipe it dry, leave it open to air, and use it again.