Instant tea: Cream processing

On cooling, a tea solution becomes opaque and lightens in color. This is due to the formation of tea cream, a colloidal substance which contains the same components as the original extract.

Tea cream is a coacervate formed of a complex between caffeine, catechins, and the oxidized catechins of black tea.

The conditions under which cream forms determined the chemical composition of the complex and its physical properties.

Cream processing can be accomplished by maintaining the temperature above 65 °C or by removal of the cream, for example by cooling followed by precipitation or centrifugation. Cream treatment is especially necessary for cold water-soluble instants, which are commonly used for beverages like ice tea.

Tea cream causes particular problems in production of instant tea for the US market, which is required to be of clear, bright appearance when reconstituted with cold water.
Instant tea: Cream processing