What to look at before you buy
What to look at before you buy: the package for the protected name and the producing area, the producer’s name and batch number, the grade, and the harvest date if printed.
If the tea is loose and visible, look at the leaf shape. A premium Longjing is flat and even. A premium Biluochun is tightly spiralled. A premium Sencha is needle-shaped or slightly twisted. A premium Maofeng is slightly curved.
Look at the colour. A fresh, well-processed green tea is bright green or yellow-green, depending on the style. A dull, brown, or greyish leaf is past its peak.
Look at the uniformity. A grade-one lot will be 90 percent uniform in shape and size. A grade-two lot will be 70 to 80 percent uniform. Bulk and bagged tea will be visibly more varied.
Weight tells you more than the tin does. 100 g of a tightly rolled green tea fills a much smaller container than 100 g of a flat, open leaf. A seller who sells by the tin rather than by weight is making the comparison harder than it needs to be.
What to smell at the base
What to smell at the base: open the package and smell the dry leaf immediately. A fresh green tea has a bright, vegetal aroma. A stale green tea has a flat or papery note.
If you are buying in person and can ask for a sample, brew it for thirty seconds in hot water and smell the wet leaf. The wet aroma should be richer and more complex than the dry aroma.
Compare the first and third infusions. A genuine, fresh, well-made green tea will hold up through three or four cups. A tea that fades after the first cup is either old or low-grade.
If the aroma is unusually strong or sweet, suspect jasmine or osmanthus scenting. A scented tea will keep the same aroma through six or seven cups; a genuine green tea will fade.
Brew temperature matters when you are judging aroma. Water at 90 °C pulls the aroma out fast. Water at 70 °C flatters a thin tea by hiding its rough edges. Ask the seller to brew at the temperature the tea is meant for.
Time the infusion as well. Aroma peaks around 30 seconds in a gaiwan and drops sharply after 2 minutes. If the seller steeps for 5 minutes before handing you the cup, you are tasting the texture rather than the aroma.
What to ask the seller
What to ask the seller: where was this tea grown and processed. A legitimate seller will name the producing area, the garden, or the producer. A fraud will hedge.
When was it processed. The processing date, not the packaging date. Green tea should ideally be sold within six months of processing.
How was it stored. A seller who cannot answer this has probably never asked the producer. One who can describe sealed, refrigerated storage from the factory to the shop is worth trusting.
Can you return it if it is not as described. A confident seller says yes. A fraud will not.
Grade labels vary between standards. GB/T 18650 sets out grades for Longjing, and its top grade is not the same as the top grade under a local standard. Ask which standard the grade comes from.
Ask for the batch, not just the name. A producer who packs in numbered lots can tell you which garden and which day a batch came from. A packer who buys loose tea at market cannot.
How to store it once home
How to store it once home: in an airtight container, in a cool, dark place. The refrigerator is fine if the tea is sealed, but take it out an hour before brewing to avoid condensation on the leaf.
Do not store green tea near anything with a strong smell. Green tea absorbs foreign aromas readily. Keep it away from coffee, spices, and cleaning products.
Do not store green tea in sunlight or near a heat source. Heat and light drive the loss of colour and aroma.
Plan to drink a green tea within six months of purchase, even with good storage. Fresh green tea is the point of green tea, and even the best storage cannot fully protect the freshness.
Portion the tea before you store it. A 250 g bag opened once a week exposes the whole bag to air every time. Splitting it into five smaller sealed packs keeps the rest of the tea closed.
Freezing works for long storage if the tea is vacuum packed first. A vacuum pack held at minus 18 °C will keep a green tea close to fresh for a year. Repeated thawing will not, so portion before you freeze.