
In 1995, the FAO (Food and Agricultural Organisation) international group established a standard on black tea (1). This standard includes a paragraph specifically on moisture content and states that tea should be packed with a moisture content of less than 4 percent.
The document also states that it is likely that during transport to the point of export and further shipment to the importing country, tea absorbs more moisture and that tea with a moisture content of 6 percent and above deteriorates in quality.( Moisture refers to the water content in Tea).