Food Manager Practice Exam

What is the minimum water activity (Aw) level that bacteria require for growth?

1. Aw .60 or greater

2. Aw .70 or greater

3. Aw .80 or greater

4. Aw .85 or greater

The correct answer is: Aw .85 or greater

Bacteria require a minimum water activity level of 0.85 or greater for growth. Water activity is a measure of the availability of water for microbial use and influences the growth of bacteria in food. At a water activity level below 0.85, the available moisture decreases significantly, limiting the ability of most bacteria to grow and reproduce. This threshold is critical in food safety and preservation practices. Understanding this level helps in determining the suitability of food products for bacterial growth, thereby assisting in effective storage and handling practices to minimize foodborne illnesses. Products with water activity levels lower than 0.85 are less likely to support the growth of pathogenic bacteria, making it important for food managers and handlers to monitor this aspect of food safety.