Water Activity, aW or ERH (Equilibrated Relative Humidity) is a measure of the free water in a product, water which is not bound into the product in any way and which is available for the growth of moulds and the proliferation of bacteria. Water Activity can have an influence on a products shelf life, odour, colour, flavour or texture.

The monitoring of Water Activity for production line and Quality Assurance purposes, its accurate measurement for research and development or product examination has become an important parameter in food and pharmaceutical laboratories.

Water activity testing can now be performed quickly and reliably thanks to the Aqualab range of instruments.