An Introduction to Sugaring
Throughout the northeastern US and eastern Canada, the term
"sugaring" is often used to describe all of the
activities associated with the production of maple syrup.
The term is even used to describe the season of the year (from
mid-February to mid-April) when the sap of the sugar maple
is collected and boiled to create that delicate confection.
The Maple Region
The commercial product of maple syrup only occurs in the
northeastern US and eastern Canada, within the natural range
of the sugar maple. Other species of maple will produce sap,
which can be made into maple syrup (black maple and red maple
are also commonly tapped), but sugar maple sap generally has
the highest sugar content and yields the most maple
syrup, per gallon of sap boiled.
Weather patterns also play a critical role in
the production of maple syrup. Maple trees only produce commercial
quantities of sap in regions where, during late winter and
early spring, freezing nights (250 F or below) are followed
by warm days (400 F or above). The science behind sap
flow is complex, but as maple trees begin to warm-up on
these pleasant spring days, pressure builds within the tree,
and sap is literally forced from any small wound or tap-hole
in the tree. In Vermont, the conditions are often right for
the sap to "run", or flow, from mid-February to
mid-April, but during this period "sap runs" (the
period of time when the sap actually drips from the tree)
may only occur five or six times. Depending on the weather,
"sap runs" can last from a few hours to several
Maple Sap Production
The size and complexity of "sugaring" operations
greatly throughout the maple industry, but the basic process
sap from maple trees (tapping) is common to all. Trees
that are twelve inches in diameter and larger are selected
for tapping. Shallow holes are drilled, into which metal or
plastic taps are firmly seated. Years ago, wooden or metal
buckets would have been hung on these "spouts",
and once filled, would have been "gathered" into
tanks on horse-drawn sleds and transported to the "sugarhouse".
Some "sugar makers" still use metal buckets, and
gather sap by hand, but it is much more common to see plastic
tubing used to transport sap directly from the tree to the
sugarhouse or a storage tank.
Making Maple Syrup
sap, as produced by the tree, is mostly water. To produce
maple syrup, a large amount of this water must be boiled-off
and the sugars concentrated. An often-used rule of thumb states
that roughly 40 gallons of sap is required to produce just
one gallon of maple syrup.
settlers often used iron kettles hung over a wood fire
to boil sap, but over the years, specially designed maple
or were developed to increase the speed and efficiency of
the boiling rocess. The evaporator uses an enclosed firebox,
or "arch" and large, flat pans with flues (deep
channels or flutes in the bottom of the pan) to increase the
heat exchange area and speed the rate of evaporation. Wood
has traditionally been used to fuel maple evaporators, and
is still used by a great many sugarmakers. However, other
fuels such as oil and propane or natural gas are increasingly
common. Today's sugarmakers continue to employ new and innovative
technologies to improve the efficiency of the
boiling process. Evaporator designs are constantly changing
to make better use of energy and to speed th boiling process.
Many sugarmakers are also adopting new technologies, such
osmosis (the process of partially concentrating sap by
passing it through a membrane through which water molecules
will pass, but sugars will not).
Sap is boiled until it reaches the required
density for maple syrup. The syrup is then "drawn-off"
into a stainless steel pail, or other container, for a final
check of density, filtering and bottling or canning. A sample
of each batch of syrup is also taken and assigned a maple
syrup grade, based on its color and flavor. Once packed
in retail or wholesale containers, properly graded and labeled,
the syrup is ready for sale.