Instant tea:

People are accustomed to seeing and using different kinds of instant coffee, but the development of instant teas has lagged far behind that of instant coffee market. In the case of instant tea, the liquor (tea brew) itself is further concentrated and dried to form a powdered or granular product. Hot water soluble and cold water soluble instant tea process includes operations such as selection of raw materials, extraction, aroma stripping, cream processing, concentration and drying.Commercial extraction techniques are designed to optimize two parameter: yield of the solids extracted from the leaf and concentration of extract solution.
As tea aroma is an important criteria to the acceptability of tea, considerable efforts have been made to preserve the aroma in the instant tea product. Most process deal with the problem by stripping the aroma of the extract before concentrating and treating it separately.
The liquor has to be concentrated to 20-40 % solids before drying, because it is uneconomic to dry from such low solids. Concentration was carried out by evaporation under reduced pressure.
For concentrate drying, Spray dryer is most commonly employed. Spray dried tea is rarely agglomerated and the most important criteria for the product are: taste, color, bulk density and moisture content. The bulk density is controlled by changing the solids concentration of the feedstock and by careful choice of atomizing system.