Bacteriophage Insensitive Mutants (BIMs) of three Streptococcus thermophilus parent strains were generated and characterized for phage sensitivity, sedimentation rate, cell chain length, phage adsorption and CRISPR loci alterations. Several BIMs showed an altered sedimentation phenotype as well as an increase cell chain length, reduced phage sensitivity, reduced phage adsorption and 100% identity in three CRISPR loci. The results show that the derived BIMs have become phage-resistant through a mechanism other than CRISPR.