How to store green tea so it stays fresh

Green tea is fragile. The same compounds that give it its bright, grassy character — the catechins, the chlorophyll, the volatile aromatics — are also what make it vulnerable. Leave a tin on a sunny windowsill and within a week the leaf will taste like hay. Store it badly and you are drinking the memory of tea, not the tea itself.

The four enemies

Tea degrades in the presence of four things: light, air, heat, and moisture. Each one does a different kind of damage.

• Light bleaches the leaf and breaks down chlorophyll, turning a vivid green dull and brown.
• Air oxidises the oils. Green tea is unoxidised by design; oxygen undoes that work.
• Heat accelerates every chemical reaction you are trying to prevent. A warm kitchen is a fast-forward button.
• Moisture reactivates enzymes and invites mould. Even a few drops from a humid cupboard can spoil a harvest.

What to keep it in

The ideal container is opaque, airtight, and small. Opaque blocks light. Airtight blocks air and moisture. Small means there is less oxygen inside to begin with, and less headspace to humidify every time you open the lid.

Our favourite is a simple ceramic jar with a rubber gasket and a clasp lid — the kind meant for coffee beans. Stainless steel tins work too, provided they are truly light-tight. Clear glass jars are beautiful and wrong.

If you buy tea in bulk, divide it. Keep two weeks' worth in your daily tin and seal the rest in a second container that you open as rarely as possible. Every time you lift the lid you trade the air inside for fresh, oxygen-rich air.

Fridge or cupboard?

For tea you will finish within a month, a cool, dark cupboard is fine. Keep it away from the oven, the kettle, and direct sunlight. A closed drawer in a north-facing room is about right.

For longer storage — or if you live somewhere humid — the fridge is better, but with a warning. Tea is hygroscopic: it absorbs moisture from the air. If you move a cold tin straight from the fridge to the kitchen counter, condensation will form on the leaves the moment the lid comes off. The fix is simple. Take the tin out, leave it sealed, and wait fifteen minutes for it to reach room temperature before you open it.

How long does it last?

Properly stored, a high-quality green tea will stay vivid for six months and drinkable for a year. After that it does not become unsafe; it becomes quiet. The brightness fades, the sweetness dulls, and the finish shortens. You are still drinking tea, but you are no longer drinking the weather.

If you are unsure, trust your nose. Fresh green tea smells like cut grass, chestnut, or spring air. Stale green tea smells like paper or old hay. Your nose will tell you before your tongue does.