It is worth reading the issue below:
http://www.propanecouncil.org/upload...rol%20Vol1.pdf
Below water-contents in propane extremely low,why not in BBQ-gas?:
In the test below no indication of the temperature itself:
and further through Google (ppt-file):
Use of Methanol To Control Freezing - Propane.tx.gov - Google-haku
Tis is the basic route for H2O-segregation in the propane corner: