Very Early Spring 2014 - Sugaring! Part II of Tapping the Sugar Maples!

Geri and Nancy being sappy!

After two weeks of collecting more sap than we had anticipated, approximately 100 gallons from thirteen trees (7.7 gallons/tap), we desperately needed to process at least some of the sap to make room for more. The "rule of thumb" is 10 gallons of sap per tap, per season, if the tree is in a forest, so just two weeks into a four to six-week season we are well ahead of pace.  We managed to process approximately 21 gallons on a Saturday, and 27 gallons that Sunday and into Monday.  The weather has been below freezing since we started evaporating, so we have gained some ground on the trees ability to produce.  Our current capacity to store sap stands at 100 gallons more or less, and about half of that depends on having snow on the ground sufficient to maintain containerized sap at low enough temperatures to prevent fermentation and souring of the sap.

According to a 2003 survey of Wisconsin producers, the evaporation process that removes 42 gallons of water from every 43 gallons of sap, leaving 1 gallon of syrup (assuming 2% sugar concentration in the sap, see Figure 1),

Figure 1: Rule of 86

is typically powered by fuel oil (49%), wood (45%), natural gas (4%), or propane (2%). [1]  In terms of cost, wood from our own forest would have been the least expensive choice, in dollars, unfortunately I was not ready to use wood as a fuel.  The use of wood as a fuel requires some sort of wood-fired outdoor cook stove, which I had not put in place.  Geri had a couple of big propane burners of the type used for a seafood boil, or for cooking a turkey in oil, together with two big "stock pots," so we decided to use the propane burners in the evaporation process.  Saturday I set up shop on the west side of the garage, and decided to move shop on Sunday to the south side of the garage, more protected from the wind.  I set up originally on the west side because there is a concrete pad in front of the garage, providing a stable location for the evaporators; my worst nightmare was that having boiled off 42 gallons I would spill the precious one gallon of syrup onto the ground!  The wind on the west side though was problematic, and seemed to make the burners much less efficient.  So, on Sunday I laid down two or three layers of heavy cardboard south of the garage, and moved the burners to the new location.

Calculation of container volumes

On one burner we set a tall pot with a capacity of about 6.3 gallons, if about 2 inches of "freeboard" was left to ensure that we did not boil over. On the other burner we set a 24 in. (L) x 24 in. (W) x 8 in. (Depth) open pan evaporator, equipped with a 3/4 inch drain and ball valve; this container, also allowing for 2 inches of freeboard, has a capacity of approximately 15 gallons.  We poured sap into the tall pot and into the open pan evaporator through cheese cloth.  The plan was to start both burners at the same time, and then to transfer liquid from the tall pot to the open pan evaporator when the level in the tall pot was reduced to 2 or 3 in. from the original 14 in., and finally, when sap in the evaporator was reduced to a depth of about 1 inch (2.5 gallons), to transfer from the evaporator to a 16 qt./4 gal. stock pot, and move to the kitchen to finish the syrup under more controlled and comfortable conditions.

On Saturday, by the time all preparations had been made, the burners were lit at about 11 a.m.  It took about 40 minutes to bring the tall pot to a boil, the open pan evaporator a little longer.  As planned, we transferred liquid from the tall pot to the open pan evaporator, and at about 7 p.m., we transferred the remaining liquid, about 14 quarts, from the evaporator, by way of the ball valve, through a fine filter to a 16 quart stock pot, and then shut down the burners and moved the process into the kitchen.  In the house, we could not help but to occasionally hover over the pot, taking in the ever-intensifying aroma of maple, and of course taste-testing the syrup!  Also, we kept an eagle-eye on the thermometer, as we had targeted a temperature of 219 degrees F as indicating

Figure 2: Rule of 86 solved
for % Sugar in Sap

that the syrup state had been achieved.  Surprisingly, in the kitchen it took another 5 hours before the sap/syrup had reached a boiling point of 218 degrees F.  In an abundance of caution, to avoid somehow ruining the batch, we decided at midnight to filter once more and decant the syrup.  Our yield was 12 cups (3/4, or 0.75 gallon) of syrup from that first 21.3 gallons of sap; which would indicate that the sugar content of the sap was approximately 3.03% (see Figure 2).  This syrup tastes absolutely fantastic, and we thought that on our next batch we would see if we could evaporate a little longer to thicken the syrup.

I put boots on the ground much earlier on Sunday, and had the burner lit under the open pan evaporator at 7:10 am, and the burner lit under the tall pot by 7:25 am.  One change to the process for the second batch, was that after transferring the liquid from the tall pot at the same point in the process as on Saturday, the pot was refilled with another 6 gallons of sap; this additional 6 gallons was then reduced to 2-3 inches in the bottom of the pot and transferred to the open pan evaporator.  So on Sunday (and into Monday), we processed approximately 27 gallons of sap, versus the 21 gallons processed on Saturday.  A second change was that

at about 9 pm on Sunday, with approximately 8 quarts of liquid remaining, we chose to "pause" the process

Geri, Chuck and Nancy decanting the syrup at midnight
on Saturday.  Beautiful color and clarity...wait, am I
discussing a gem?  Indeed I am!

and get some sleep.  We turned off the burner, covered the pot, and put the pot on the front porch where it was cold enough to prevent fermentation.  On Monday Geri resumed the process, and ultimately bottled 13.5 cups of syrup, having halted the evaporation process at 220 deg F., which would indicate that the sugar content of the sap processed was approximately 3.7%.  Again, prior to decanting, she passed the syrup through the filter to remove the "sugar sand." [2]  The taste was, as now expected, intense and superb!

Sunday night, while we were processing the second batch, we tried some of our first batch of maple syrup over Geri's homemade apple pie a la mode.  Wow!  What a flavor combination, and the intensity of our maple syrup's flavor put store-bought substitutes to shame!

The intrepid sugarers, Chuck, Nancy, Geri, John and Dennis

My advice is, that if you have access to maple trees, take on the production of maple syrup!  It is somewhat labor and energy intensive, and it is also more than equally rewarding.  The process can be set up with a very low investment, using milk jugs and tubing from your local hardware store, your camp stove or outdoor range, appropriately sized pots and pans, some cheese cloth and felt for filtering, and a candy thermometer.  Go for it!

As always, your comments and criticisms, your inputs and acknowledgements, are welcomed, and will help me to improve my posts.  Please "follow" the blog.

-- John, 26 March 2014

West side of the garage on Saturday.  Open pan evaporator on the left, cardboard wind break to the left of the pan and burner; tall pot on burner to right, surrounded again by cardboard wind break, under the watchful eyes of John and Chuck.  Tarp rigged up to prevent leaves, bugs and other detritus from falling into the evaporators.  It took a little more than two full 20 lb. propane canisters for each batch.

[1] "Maple Syrup Production," University of Wisconsin - Madison, College of Agricultural and Life Sciences, Web, Retrieved 25 March 2014 from http://www.uwex.edu/energy/maple.html

[2] Sugar sand, n.d. In Wikipedia. Retrieved 26 March 2014 from http://en.wikipedia.org/wiki/Sugar_sand