This document discusses the hurdle concept of food preservation, which uses multiple preservative factors or hurdles to disturb the homeostasis of microorganisms and prevent them from multiplying. The hurdles, including temperature, water activity and pH, interact complexly and must be high enough that microorganisms cannot overcome all of the hurdles present in the food product, causing them to remain inactive or die off. The hurdle concept illustrates that the combined effects of various preservation factors are important for microbial stability in foods.