Last Spring, we transitioned to a maple syrup operation that was set up with vacuum lines and included a beautiful western red cedar sugar shack complete with a traditional cupola.  The shack had not been used since the lines were installed, leaving a little bit of preparation before the season.  We needed a way to get concentrated sap to the sugar shack and ultimately, to the evaporator inside.  This was addressed by breaking the challenge into steps. 

  1. The sap needed to be transported and deposited into a stainless tank at the sugar shack. 
  2. A platform was required so that the tank would be at a sufficient height to permit gravity flow to the evaporator.
  3. The tank had to be connected to the float box at the back of the evaporator.
  4. The tank is uncovered, so it needed to be protected from the environment to prevent introduction of debris and insects.  The concentrated sap also had to be kept from freezing.

Getting concentrated sap to the sugar shack was solved by running a line high in the trees along the road between the sap tanks and the sugar shack.  The line could be connected to a food grade gas pump to draw sap from the main storage tank across to the sugar shack. 

Building a platform for the storage tank at the shack was straightforward.  It was designed with plenty of reinforcements to hold the weight of a full tank of concentrated sap (240 gallons) and a 60-gallon water tank.  The platform height is five feet and there are two shelves below it for storage. 

We ran a short line from the tank to the float box.  This required drilling a hole in the back wall of the sugar shack to accommodate the line.  A Y-joint was installed on the line so that we could connect both the water tank and the sap tank.  Valves were attached to each tank to control flow.  The design enabled sap to be sent to the float box through gravity feed. 

The float box controls sap flow.  Sap remains at the same level in the float box as it is in the back pan.  Inside the box, the float rises with the sap.  When sap reaches approximately one-half inch above the top of the flues in the pan, the float closes a valve stopping the flow of sap into the float box.  As water boils off and sap moves to the next pans, the volume in the back pan goes down.  The float also goes down, opening the valve and permitting more sap to flow into the float box.  When the sap is boiling well there is a constant flow of sap into the float box and back pan.  This flow reflects the evaporation of water from the sap and the continuous draw of maple syrup from the front pan.

Why did we include a water tank?  When the last of the sap is used up, water needs to replace the sap feed into the float box.  Without this step, the back pan would burn.  Water also pushes the remaining sap through the channels in the back pan and allows the rest of the sap to cook down, eventually replacing it with mostly water.

The last step was protecting the sap in the tank at the sugar shack.  The back of the sugar shack had a roof overhang.  This provided the perfect space for the platform holding the tanks.  We enclosed the space with western red cedar to create a closed and protected environment.  This room prevented the sap from freezing and kept it clean.  We added a door for convenient access from outside.  The enclosed space was accessible to the sugar shack through an existing door.  This job was finished as the sap began to run.

Improvements to the enclosed space waited until the weather warmed up.  The boards were stained to match the rest of the sugar shack and the door was painted.  The red did not turn out as we expected but changing that can wait until another day.  The sugar shack has a classic cedar shake roof.  The section above the enclosed space had a lot of moss growth and warranted being replaced.  This presented an opportunity to build overhangs to protect the walls from rain and snow.  Each side was extended 12 inches and the front 18 inches by building box frames that were then stained and attached to the faceplates.  The existing roof was removed, plywood was installed to span the extensions followed by tar paper and shingles.  This was a great building improvement and it taught the boys some roofing and construction skills.


Leave a Reply

Your email address will not be published. Required fields are marked *