Get water activity (aw) results fast, from New Zealand's premier water activity testing lab, using the world's leading . Testing is performed in accordance with the relevant AOAC method and results are generally available within 4 hours of samples being received.
All water activity analysis is performed on the Decagon AquaLab, the world's fastest and most accurate water activity instrument.
How do I Relate Moisture Content to Water Activity?
The relationship between moisture content and aw for a product is called a 'moisture sorption isotherm'. You can determine your product's moisture sorption isotherm with our .
What is Water Activity?
Water Activity (aw) is the critical factor that measures the shelf life of food products. While temperature, pH and several other factors can influence microbiological activity, water activity is probably the most important factor.
Water activity is a measure of the ‘free’ water in a food sample, as opposed to the ‘ bound’ water. Most bacteria for example, do not grow at water activities below 0.91 and most moulds cease to grow at water activities below 0.80. By measuring aw it is possible to predict which microorganisms will and will not be potential sources of spoilages.
Download our showing the critical aw limits for different micro-organisms.