Abstract: The present invention relates to the field of food fermentation procedures involving lactic acid bacteria and in particular to improving the quality of dairy products like acidity, post-fermentation acidification, aroma, flavor, mildness, consistency and texture. Specifically, the present invention provides a method for making dairy products using the thermophilic Streptococcus thermophilus and the mesophilic Lactococcus lactis carrying plasmids encoding small heat shock proteins which allow fermentation to be carried out at temperatures higher than the regular fermentation temperatures. The thermophilic and mesophilic lactic acid bacterial species expressing said small heat shock proteins also exhibit increased tolerance to lower pH and higher salt concentrations as well as reduced sensitivity to bacteriophage attack at the elevated fermentation temperatures.