The aw of the syrup was measured in duplicate with an AquaLab
Series 3water activitymeter (Decagon Devices, PullmanWA) according
to the manufacturer's instructions. Certified water activity standards
with aw values of 0.760 ± 0.003 (6.00 mol/kg NaCl) and 1.000 ± 0.003
were obtained from the manufacturer.
The estimated sugar content as °Brix was determined by two techniques
used by maple syrup producers. Except for the cases where
there were mold-damaged samples, the readings were taken in all
three remaining samples.