The present invention relates to a method of producing a beverage by: - providing a pasteurised or sterilised aqueous liquid containing 0.5-8 wt. % of dissolved soy protein and 0-0.2 wt.% of dairy protein; - inoculating the pasteurised or sterilised liquid with a thermophilic lactic acid bacterium containing starter culture; - fermenting the inoculated aqueous liquid by incubation at a temperature in the range of 40-48°C for 0.5-24 hours to obtain a fermented product having a viscosity at a temperature of 7°C of less than 50 mPa.s at 100 s-1; wherein in total less than 6% disaccharides by weight of the fermented product are added before, during or after fermentation and wherein during fermentation the following changes in concentrations of flavour compounds occur: lactate concentration increases with at least 500 ppm; diacetyl concentration increases with at least 0.3 ppm and/or acetaldehyde concentration increases with at least 0.05 ppm; concentration of n-hexanal decreases by at least 60%; at least two of n-pentanal concentration, n-heptanal concentration, n-octanal concentration and n-nonanal concentration decrease by at least 50%. The present method enables the effective removal of soy off-notes as well as the preparation of fermented substrates with a desirable flavour profile that is similar to that of fermented dairy products.
