Maple Syrup making

[brianv]

Hi all!

For the last few years, I've been making a moderate amount of maple syrup from the maples on my property. I've alternated between evaporating over a hearth made from cinderblocks with a homemade chimney, boiling inside the house (and dealing with ventilating lots of moisture), and a propane burner (burned way too much propane).

I'd like to cut down on my inputs (ie, wood and time) as much as possible, and I am very interested in what's been done here over the years as I've watched the batchbox and now DSR / DSR2 designs evolve. Perhaps my best plan forward would be a simple rocket stove with a pot on top, but I'd like to see if anyone has any other thoughts on the best way to induce prolonged, vigourous boiling without needing to feed the stove any 10 minutes - I'd love to be able to check on it hourly, at least in the early stages when I'm trying to boil off as much moisture as possible as quickly as possible.

The other side of the coin is form factor - I have done most of my boiling in large stock pots, which nearly as efficient as you would get with a larger but shallower evaporation container due to the relevant difference in evaporation area.

Has anyone ever tackled an application like this?

[emilsagroforest]

When we started making syrup we used a homemade finishing pan about 24"x 36" and 4" deep. We used a barrel stove kit and cut the top of the barrel to set the pan into and then used a large canning pot with a spigot as the pre-heater above and behind the pan. It worked pretty well but it required constant care. If you walked away the syrup could burn and warp the pan or the sap would overflow and kill the boil.

We have since upgraded to a 2'x6' leader drop flue evaporator and now the sap feed is regulated with a float valve, so that's one less task but still a concern, (should it clog or stick open). The main task is maintaining constant heat on the pans which requires adding wood every 8 minutes or so. It uses a lot of wood and a ton of fuel is wasted out of the stack. The stack is 7".

I too have been following the DSR2 build and wonder if it would be worth trying to build one inside the firebox. My concern is that since the operation is rarely less than 8 hours long, after a while the ashes will build up and not allow any room for the fuel.