Price of the test:
$46 per analysis
Nearly all foods and food products
Samples containing high levels of propylene glycol
Limit of Detection:
0.250 aw units (lower limit)
Sample Size Requirements:
Water Activity Meter
(Water activity, aw is the ratio of vapor pressure of the water in the sample to the vapor pressure of pure water at the same temperature)
Turn Around Time:
7-9 business days
Is Rush Available?
This method is a measurement relating to the free, unbound water present in food and food products.
The atmosphere of a special sampling cell is evacuated, repressurized and then measured manometrically. The results are correlated to water activity in the sample
Water activity has little, if any, relationship to the total moisture content of the food. Water activity does provide a means of assessing the storability and bacterial susceptibility of shelf-stable foods. It is known that microorganisms cannot survive below certain aw levels, the level being dependent upon the type of microorganism: Botuli at <0.93; Bacteria at <0.86; Yeast cells at <0.78 and Mold spores at <0.65.