Aqueous extraction of black leaf tea. III. Experiments with a stirred column*

Summary Stirred batch aqueous extractions of black tea at 5:1 water‐to‐tea mass ratios showed stirring reduced yield of solubles in extract and that tea solubles may be grouped into three classes: effectively instantaneously soluble, rapidly soluble and slowly soluble, apparently following independent first‐order solution processes. Rate equations are given for dissolution of soluble tea solids from leaf at 60, 80 and 100°C and their application to continuous extraction discussed.