Does the boil evaporation rate change with outside temp.? I have my system dialed in almost perfectly, except for the evaporation rate. I brew outdoors year 'round, and my evap rate seems to change depending on the air temp. I have a mark on my propane regulator that I set to when boiling, so I know the flame is always the same, yet my evap rate seems to vary, especially with colder temps. During colder weather, it appears I am getting a higher evap rate (less wort collected). Any ideas?