Ranch dressing, nacho cheese sauce, chocolate syrup, and caramel dip all have high water activity values.  What assures their safety?  Combining good manufacturing methods with either low pH or water activity (or both).  The foremost quality measurement on sauces and dressings is usually pH, and many are acidic enough to hinder microbial growth without help from water activity.  However, water activity can still act as a hurdle to hinder microbial growth, providing extra protection against potential problems.

Jams and Jellies

Jams generally have a large amount of sugar in them, and depending on the fruit involved, may also be somewhat acidic.  In less acidic jams, water activity acts as the control point because sugar’s ability to reduce water activity hinders the growth of microorganisms.

Fast Answers

Quality control in sauces and dressings requires fast results, and confirmation products meet specifications.  The AquaLab 4TE gives readings in around 5 minutes, without sample prep.