If the following situations occur to the tea, whether it is within the shelf life or not, such kind of tea can no longer be drunk.
1.The tea has obvious color change.
It is normal that the color of tea will become darker after a long time of storage, for example, after about five years of storage, the color of white tea will turn into dark yellow then into reddish brown from apricot yellow, but the tea infusion is always transparent and bright. But it should be noted that if the tea infusion not only gets darker, but also becomes dark brown and turbid, not bright at all, then such kind of tea is likely to be deteriorated.
2.The tea is tainted by peculiar odor.
Tea has a strong adsorption ability. If it is stored together with things with peculiar odor or is not sealed before it is put into the refrigerator, then it is prone to be tainted by other odor. If the tea has an obvious camphor ball smell or oil smell, then such kind of tea had better not be drunk.
3.The tea is softened or gets moldy.
The max moisture content of tea is supposed to be about 5%. If the moisture content exceeds 10%, tea easily become damp and moldy. Normal tea leaves feel crisp and are easy to break. If the tea became soft and wet, or smells moldy, then the tea must be absolutely deteriorated and can no longer be drunk.