Escherichia coli inhabits multiple environments that contain varying physical stresses which emphasize the importance of adaptation. The large pangenome of E. coli can account for some strain-to-strain variances in phenotype, but phenotypic plasticity may be another key factor. The key behind phenotypic plasticity may be transcriptional regulators such as the sigma factor RpoS. The extent of phenotypic plasticity and possible mechanisms in stress conditions has not been heavily studied in bacteria. We looked at the presence of plasticity in the growth rate of E. coli under a hyperosmotic condition. RNAseq was used to explore the connection between RpoS and phenotypic plasticity. The conserved genes within all the isolates and their connection to hyperosmotic stress were also explored. Phenotypic plasticity of growth rate was observed among the strains on a phenotypic level. Genes associated with osmotic stress, fermentation, and cell envelope synthesis were found to be significantly expressed within all isolates.