Basic knowlegde on knowing to keep tea and consume tea

Usually, tea can be kept for 1-2 years if giving a good seal. Tea should be kept in dry, drak, low-temperature and free of bad odours places. To identify whether the tes still can be drunk, you can smell whether it has moldy odor; whether the green tea turns to black, the tea water turns dark; whether the tea still tastes rich and fresh.