The invention provides Streptococcus thermophilus mutants, such as DSM22933, which have improved texturizing properties. The strains have: (i) a mutation in the branched chain amino acid transport ATP-binding protein LivG (TC 3.A.1.4.1) gene; (ii) a mutation in the ABC transporter permease protein gene; and/or (iii) a mutation in the peptide deformylase protein gene. The invention, furthermore, relates to compositions, such as a starter culture, comprising one or more of these mutants, to fermented products made using these mutants and to the use of the mutants and compositions of the invention.