A method was developed to combine qualitative and quantitative information to predict possible growth of microorganisms in foods. The pH, water activity, temperature, and oxygen availability of foods are coupled to the growth characteristics of microorganisms. Therefore, a database with characteristics of foods and a database of kinetic parameters of microorganisms were built. In the first database, a tree structure based on physical similarity was built, for the case that information about the characteristics of a particular food is unknown. By comparing with similar products at the same level of the tree or the level above, the product information can be estimated. A method is developed to make an estimation of the microbial growth kinetics on the basis of models. This is done by introducing a growth factor, which can be calculated on the basis of readily available data from literature. Since all the information can be altered, the system can give better predictions when more and more accurate information is added.