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The Science of Sugaring

This is the busiest time of year for sugar makers.  We have to be ready to make syrup when the sap is flowing, and all other activities in our lives must take the back burner during this busy time!  Sap started flowing early this year, in mid-February.  Luckily we had all of our trees tapped and were ready to go when the sap was ready to flow!  March was a very cold and snowy month, so we made very little syrup during March.  Sap started flowing again in late March and first two weeks in April were very busy! The season typically ends in the second or third week of April, depending on Mother Nature.

Making maple syrup

When the temperatures warm up above freezing during the day, we turn the vacuum pumps on and make sure all of the equipment is ready to go in the sugarhouse.  The vacuum pump pulls the sap through the pipelines in the woods and into a releaser in the sugarhouse.  The sap is pumped over to one of three raw sap tanks and continues to collect there until we have enough sap to boil.  In general, (depending on the sugar content of the sap), it takes about 40 gallons of sap to make one gallon of maple syrup!

We first send our sap through our Reverse Osmosis machine, which removes about 80% of the water from the sap and concentrates the sugar content from about 2% to about 20%.  The purified water stream, called permeate, is collected in large tanks and is used for cleaning in the sugarhouse.  The concentrate stream (containing all the sugar from the sap) goes into a tank which feeds the evaporator pan.  The evaporator boils the concentrate down until it reaches the appropriate density for syrup, at which point it exits the evaporator pan into a holding tank.  Filter aid (diatomaceous earth) is added to the holding tank and mixed into the hot syrup, and it is then pumped through a filter press where the impurities, called niter, are trapped in the filter aid inside the press, and pure liquid gold exits the press through a transfer hose into a large, clean barrel, or into our bottling machine, where we can fill any size bottle or plastic jug.


As the sun gets stronger and the temperatures continue to rise, there are fewer nights where the temperatures get below freezing, which is important for good quality sap production.  As the trees begin to bud, sap production decreases, sugar content decreases, and sap quality deteriorates.  So you may be wondering, what do peepers (small tree frogs) have to do with making maple syrup?  Well, when the peepers start peeping, it is a sure sign that sugaring season is coming to an end!  Without fail, within two or three days of hearing the peepers start making their high-pitched mating calls at Snowshoe Pond, we are boiling out the evaporator and making our last syrup of the season.   Now it is time for massive cleaning in the sugarhouse, and for pulling all of those taps out of the trees.