The present invention relates to a process of producing a black leaf tea product with a bright coloured liquor. In particular, the present invention relates to a process for the preparation of a black tea product comprising the step of adding one or more polycarboxylic acids and one or more enzymes capable of degrading plant biomass to a leaf tea starting material before or during a step of fermentation or incubation of the leaf tea starting material. The present invention also relates to a black tea product obtained by the process.