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Maple Syrup

bill nye_3
bill nye_3 Member Posts: 307
 How would I determine the optimum firing rate for an oil burner on a maple syrup evaporator?

No more wood fire for this farmer, he just bought a new evaporator that has a burner. I have not seen it yet. He says it will fire between 2.50 and 5.00 gph.

He asked me to determine the most efficient firing rate and adjustment. This thing is supposed to have all the bells and whistles. It has a secondary heat exchanger right near the flue as he explains it, if I understand correctly.

Maple syrup traditionally was a 40:1 reduction. Now he has a reverse osmosis thing that reduces it to 18:1. The sap gets collected with vacuum pumps now. 

Sounds like he has shelled out some serious coin on this stuff.

My theory is if the firing rate is too high I will have a high stack temp and be wasting fuel. Too low and I will be burning fuel and not getting it hot enough to evaporate quickly? How would you find the most efficient firing rate? Oil is over three bucks a gallon here.

Maple syrup must be denser than water? Does it take more heat to evaporate than water? Wish I could call my cousin the science guy.

I was hoping to show up with some knowledge when I go to set this burner up. The sap is already running, He will most likely be starting up very soon. I really don't know anyone I could ask. My brother used to make syrup be he used cords and cords and cords of wood.

Bill Nye


  • tim smith
    tim smith Member Posts: 2,738
    Re: firing rate

    Not an expert on maple syrup heaters but I would think around a 350 degree net stack or so with 10% - 10.5%  co2 would be getting close. What y all think.
  • bill nye_3
    bill nye_3 Member Posts: 307

    Thanks for the links, very informative.
  • icesailor
    icesailor Member Posts: 7,265
    Maple Syrup Reduction:

    The idea is to reduce the water level in the sap by boiling out the water. As you boil out the water, that boils off at 212 degrees,  the syrup becomes more concentrated by the loss of water. Leaving a higher sugar content. It's like making gravy. You boil the gravy base until you get the desired taste and thickness. .

    As fare as the modern end of it, the vacuum may be used to lower the boiling point of the water while under vacuum and "distill" the condensed water and pulling it off.  As far as how high you want to fire the unit, it would depend on how fast you want a boil or how big your tanks are. Sounds like a cool rig. You'll learn something.
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