Testing Cottage Foods for Aw |
What is Water Activity? Water activity (Aw) refers to the amount of free water that is available in food for microbial growth. It is a measurement of the water that is not bound to components in the food, and therefore available for microbial growth. Water activity is measured in values from 0.0 to 1.0. The lower the Aw value, the more "dry" a food item is considered. However, water activity should not be regarded as moisture content. The scientific definition of water activity refers to its measurement in equilibrium relative humidity. You can think of water activity as the humidity of a food. When water activity is above .85, several pathogenic bacteria can grow and may cause food poisoning. MN's cottage foods law requires cottage foods to have a Aw value of .85 or less to prevent the growth of potentially harmful bacteria. The water activity of a food product can be lowered in a variety of ways.
Excerpted from "Understanding the Water Activity of Your Food," Virginia Cooperative Extension, 2012. | Using The Elitech GSP-6 Meter to Measure Water Activity in Cottage Foods
| Order the Elitech GSP-6 Water Activity Kit You order these kits from our MFMA Store. $85 (includes taxes, S & H)
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