A process for making a powdered precursor for preparing an acidic beverage upon admixture of the powdered precursor with a liquid, the process comprising the steps: (a) preparing a first slurry comprising a protein source and a stabiliser, said first slurry having a neutral or an acidic pH； (b) adjusting the pH of the first slurry, if necessary, to a value in the range of from 2 to 6, preferably from 3.5 to 4.2； and (c) spray drying the first slurry after step (a) or step (b).
