We sell tea by weight, starting from 10 grams. Not out of eccentricity: at per-gram prices, packing everything into ready hundred-gram bags would mean buying a month’s supply just to try something. And tea is a thing you do not know until you have brewed it.
What that means in practice
10 grams is enough for two gaiwan sessions or three to four brews in a teapot. Enough to find out whether a tea speaks to you. It is a trial portion, and that is what it is for.
50 grams is roughly a month, if you drink that tea every other day. A sensible amount for something you already know and like.
100 grams is for one or two favourites. With larger amounts storage starts to matter: tea opened daily lives shorter than tea kept sealed.
How to store it
Three things do the damage: light, moisture and other smells. Best is an opaque tin with a well-fitting lid, in a cupboard rather than on a windowsill.
Dry leaf behaves like a sponge for smells. If it stands next to coffee, caraway or open vanilla, within a week it smells of them and not of itself. The same goes for the fridge, which adds moisture every time it is opened — tea does not belong there.
The freezer is a last resort sometimes used for greens in China, but it demands airtight packaging and defrosting without opening. At home it usually does more harm than good.
How long it lasts
Greens and yellows are the least durable. Freshness is their main virtue, so drink them within a year of harvest, ideally sooner. After two years they can still be brewed, but the floral fragrance is only a memory.
Whites take time well and grow sweeter and more honeyed over the years. In China they say: in the first year tea, in the third medicine, in the seventh treasure. A proverb, not a prescription — but there is something in it.
Red teas and oolongs comfortably last two or three years without visible loss.
Dark teas — pu-erh and Liu Bao — are the only group that genuinely gains with time. They ripen for years and need access to air, so they are kept differently: in paper or a cardboard box, not in an airtight tin.
A few small things
Do not decant tea into a clear glass jar, however good it looks on a shelf. Light is worse for leaf than time.
Do not keep the tin above the cooker or next to the kettle. Steam and heat do their work faster than you would think.
If you buy several kinds at once, label the tins straight away. A week later the dry leaf of Shou Mei and White Peony looks the same, and nobody can tell from memory.