The disclosure relates to a method of preparing a liquid nutritional composition. The method comprising heat-treating a liquid composition having a pH of between 4 and 6 and comprising about 2% to about 25% by weight of non-hydrolysed whey protein, wherein the whey protein comprises or is provided by an ingredient that comprises at least about 55% of the heat-denaturable protein present in a denatured state, and wherein the heat treatment has an Fo-value of at least equivalent to 900 degrees Celsius for 40s, and b) recovering the liquid composition, The recovered liquid composition has a viscosity of less than 200 cP when measured at 200 degrees Celsius and shear rate of 100 s-1, an average particle size of less than 20 micrometres as categorised by the volume weighted average particle size parameter D[4,3], and/or exhibits essentially no observable gelation or aggregation. The composition may further have from 0 to about 30% by weight fat and/or from about 0% to about 45% by weight carbohydrate.
