Sunday, March 23, 2014

The Making of Maple Syrup

I recently got to present at Sustain Jefferson's Makerspace Discovery Meeting.  I exhibited the maple syrup rocket stove that I worked on building with Greg David and the top bar beehive that I am working on making.  I actually was featured in a picture on the Watertown Daily Times front cover.  The makerspace will be a place for people to get together in the community to work on projects such as wood working, metal working, knitting, crafting, sewing, incubate business and much more.
The presentation I gave highlighted the improvements to the maple sugaring operation over the past 6 years.  I wanted to share some of what I have done over the past years here.

 The original way of tapping and collecting the sap.  We now use a 5 gallon bucket that sits on the ground and is connected to the spile with a piece of flexible hose.

The first year I made a crude fire box with concrete blocks and a wire grill rack to support flimsy aluminum pans.  It worked okay but wasn't very efficient.

Still using the same system - different view.
The small firebox between the concrete blocks.

A slightly more elegant system with mix-matched diameter chimney pipes.

An improved system.  Still with mix-matched chimney pipe but now the flimsy aluminum trays are sitting on top of a turkey smoker (large metal box) with sides on it to block the wind.

Automatic sap injector.  A food grade rain barrel and hose that would allow a direct flow of sap into the pans.

The automatic sap injector line running downhill to the operation.  Note the use of a 2X4 to hold the chimney up.

The automatic sap injector feeds into copper coil around the chimney to pre-heat the sap.  This year the pan became stainless steel catering pan and is cut into the turkey smoker.  The first boil of that year had the pan sitting on top but Alicia and Carlo noticed that it wasn't transferring heat that well and began to punch holes through the fire box.

The new shiny door!

Trying to increase surface area and chimney length to get a more efficient boil.  The pan rested on the wire rack but unfortunately didn't get very hot.

The front view of the evaporator.

There always is a lot of this - sitting a waiting.

Last year at the farm we boiled the sap on a propane cook stove.  Gladly this year with the high propane prices we are not.

I tried to make a small rocket stove out of bricks but unfortunately the chimney wasn't very tall and it didn't draft well.  We ended up with ash in the syrup which wasn't so yummy.

The rocket stove in action and slowly boiling away the sap.
This is the firebox of the rocket stove.  It burns efficiently but will need some improvements before it can really keep up with the evaporation ability of the other new evaporator.
The big evaporator built this year.  It holds around 7 gallons of sap at a time and we were able to get a 3 gallon/hour evaporation rate this year.  I think we can easily increase that if we get it a little bit more level, have more draft control, and tend it more frequently for the next boil down.

The three trays steaming and boiling away.
The firebox is lined with bricks which help to hold the heat in and a baffle at the back forces the flames to touch the pans.  It is still warm the next morning and was still smoking some 12 hours after we finished.
I'd love to hear any thoughts on ways to improve it or if you have any questions on making syrup yourself.



  1. Amazing writeup Alicia and Neal, I love how many different methods you've tried, shows a lot of ingenuity and creative problem solving. Very helpful as I try to cobble together an evaporating system of my own. Here's hoping your efforts are sweetly rewarded!

  2. PJ, thanks for your comments. We were rather successful with the help of some friends and neighbors efforts and sap. We are already thinking about ways to improve it for next year. What did you end up trying this year.