Separate mathematical models for each of six bacteria that relate organic acid minimum inhibitory concentrations (MICs) to acid molecular properties were previously constructed and validated. MICs were determined for each of eight acids selected to have maximum modeling power for each of four additional bacteria (Listeria innocua, L. ivanovii, Pseudomonas aeruginosa and Oenococcus oeni). MIC models as a function of acid molecular properties were constructed for each organism using partial least-squares regression; these were very strong, with best prediction R 2 values ranging from 0.905 to 0.947. The patterns of the MIC model coefficients were compared with those of the six bacteria models constructed previously. Together these represent one pattern of acid susceptibility and four different patterns of acid resistance (Lactobacillus-type, E. coli-type, Listeria-type and Pseudomonas-type).