Manufacturing of instant tea
The commercial production of instant teas began in the 1940s, and this form of tea has grown in popularity in the United States to the extent that it now comprises 42% of tea sales in the country.
These products are hot and cold water soluble, iced tea concentrates, carbonated tea etc.
Instant tea processing begins with extraction of the selected tea leaf blend. Generally, a fermented black tea type is used, chosen of reddish color, relative freedom from haze and strong flavor when brewed.
It also may be made from semi-fermented or green dried tea leaves, it may also be used of partially fermented undried leaf.
About 10 parts of water are combined with 1 part of tea leaves by weight in the extractors, and extraction is carried out at temperature between about 60 and 100 ° C for 10 minutes.
In the case of instant green tea it is also necessary to ensure the leaf is heated to at least 70 °C to inactivate enzymes.
The final extracts contains about 4% solids, which represents approximately 85% of the soluble solids in the leaves.
Concentration of the extract is effected by evaporation of the water under reduced pressure at a moderately elevated temperature.
Spray dryers used in the production of instant tea usually complete the drying operation with the drying chamber, producing a powder with a moisture of 3-5%.
