Different parts of your body prefer a more alkaline environment (i.e. intestines), while other parts are more acidic (i.e. the stomach). Just like your tissues, bacteria also have a preference. The degree of acidity or alkalinity is expressed as pH. pH is measured on a scale from 0 (acidic) to 14 (alkaline/base), with 7 being neutral. (see the diagram to your right)

When it comes to bacteria, most grow best at a slightly acidic to neutral pH. Similarly, most potentially hazardous foods have a pH hovering from 4.6 – 7.0. This creates optimal growth opportunity for bacteria in food. The acid/alkaline balance of food is one such method that food processors and chefs can play with to discourage bacterial growth. Adding lemon, salt, or sugar, for example, can alter the pH of a food, making it less hospitable for bacterial growth. Decreasing or increasing the PH outside of the optimal range, is one tactic that can be used to minimize the contamination potential of a food, where viable to do so. It is not, however, a full proof solution, as not everyone wants to eat acidic or sour chicken!