A tablespoon is a non-scientific but very widely used unit of volume, which works very well in cooking, herbal medicine, etc. It is represented by a capacity of one tablespoon which varies from roughly 15 mL in the US to 20 mL in Australia.
1 If tea is properly stored, it can potentially last up to a year for green and black teas. White tea lasts about six months before it isn't as good in quality as when fresher. Stale tea (or bad tea) will taste flat, as if you're drinking paper.  Glass or ceramic containers are fine provided that they're opaque.
Wondering how long your expensive loose leaf tea will last? It all depends on how you store it. This article will enlighten you on the do's and don'ts of properly storing gourmet loose-leaf tea to make your tea last all through next winter. 1. Keep fresh tea away from air, heat, light, and moisture.