Alcontrast - I also started with a turkey fryer propane burner and pot. It works, and we made some fine syrup that way. We stored the partially boiled sap in the refrigerator in a covered pot between boils and the finished syrup came out very good (clear light amber).
This year we upgraded to a “hotel pan” on the same turkey fryer burner. With the volume of sap you have, I think you could immediately benefit from the same change.
A “hotel pan” is the slang term for a steam table pan. We are using a “full size 6" deep” pan. Its just under 21" x 13". Google that description and you will see them. They are about $20 and provide for more than 2.5X the surface area of sap as compared to our 11.25" turkey fryer pot. Surface area is a key factor in evaporation rate.
Our evaporation rate more than doubled with this change. The steam table pan & propane burner is good for about 1gal per hour of evaporation. Most importantly, because we are using the same burner, the fuel consumption per hour is unchanged, but the evaporation rate is more than double. The other way to look at that is to say that by changing from the fryer pot to the steam table pan, we are using about half as much propane to do the same work. We saved the cost of the steam table pan in propane savings very quickly.
In fact, I added a second burner and pan when I saw how much better it worked. I have discovered/proven that propane is a very costly way to boil sap. But, propane is very convenient, and quick to start and stop. There is good reason why most people working with any real volume use wood fires. Im not quite there yet, but maybe some day.
Good luck and have fun!IMG_7155.jpg
2017 - 5th season
22 old fashioned metal taps and buckets
12 on gravity / tubing
17 year old willing to collect in rain, sleet, or snow
30 gal blue barrel for sap storage
2 full size steam table pan block arch with two propane burners & digital thermometers
10x10 sugar house and brewery