The development of a method to predict microbial food safety and quality is described. The manufacture of a food from its ingredients is simulated, using a recipe. Food engineering heuristics are combined with models developed in predictive microbiology. Parameter values of ingredients of foods, such as water activity and pH, and models for microbial growth and decay are used for the prediction of the kinetics of microorganisms generally found in ingredients. The values of these parameters are collected in databases. If required information is lacking, methods are described for making reliable guesses of the parameters. Food quality can be calculated as a function of fluctuating temperature in time. Several food distribution chains can be simulated in order to assess the influence of distribution chains on food quality. The described methods were implemented into a computerised decision support system that can be used in food production, product development and training. In the future it may be possible to apply specific expert knowledge in production and development of foods to improve the quality of prediction.