The present invention relates to a process for preparation of a soy protein containing acidic beverage that shows good physical stability after heat preservation. The process comprises the step of providing an aqueous composition having a pH of between 3.0 and 5.5 comprising 0.2 to 5 wt% of soy protein and at least 0.1 wt% of water soluble soybean polysaccharide as a stabiliser wherein the weight ratio of the soy protein to water soluble soybean polysaccharide is between 7:1 and 1:2 followed by heating the aqueous composition to a temperature of more than 100 °C for at least 4 seconds. Further to this the invention relates to a beverage obtained by this process.
