Processing Maple SAP

Checking on the boiling process of the sap.

The sweet process of turning sap to syrup happens in a sugarhouse.  But this sugarhouse is quite different from the one Hansel and Gretel happened upon – a fully equipped sugarhouse contains a great deal of equipment, including a storage tank, an evaporator, a readily accessible fuel supply, and perhaps modern technologies such as a reverse osmosis, preheating, or vapor compression systems. Other items include facilities to store and package syrup, and perhaps a kitchen for production of other products such as maple candy.

Traditionally, wood was used to fuel the evaporators to produce maple syrup.  Wood fires created a homey atmosphere that many maple producers believe is part of the perfect maple experience.  And wood is easily available as a fuel, aiding in forest management when diseased and fallen trees are used.  But most wood-fired evaporators are inefficient compared to modern evaporators powered by other fuels.  It takes one full cord of wood (128 cubic feet) to produce approximately 25 gallons of syrup.

Greg Zimpfer of Attica drains freshly
made syrup from the evaporator.

It takes time to make maple syrup.  Water is removed from the sap by heating it, concentrating its sugar from two percent to approximately 66%.  In modern evaporators, sap flows into a “sap pan” and is heated, allowing evaporation.  Then the concentrated sap flows into a “syrup pan” for finishing.  The finishing pan typically is an open-topped large pan heated from below.  It allows a controlled removal of syrup as it reaches the final stages of processing, creating higher-grade, uniform syrup.

Most commercial operations rely on hydrometers or refractometers to accurately assess sugar concentration.  Non-commercial operators may use “sheeting”, a process that takes a flat edge scoop and dips and removes it from the nearly-finished sap. The flat edge sheds the syrup in “sheets” if it has reached the correct sugar concentration.

Commercial producers often store syrup in 30-gallon drums during the production season. Syrup in drums can be sold in bulk to various outlets or repackaged by the producer into smaller containers.

Before packaging, maple syrup is filtered to remove precipitates that form during processing.  After filtering, syrup is graded according to the amount of light passing through it.