Out in the maple orchard there are a few days of hard work, then syrup season is over. When the nights are below freezing and the days are warm and sunny with little breeze, sap runs freely from the sugar maples. Good sap is clear, like water but if you taste a drop, it is sweet.
Every day the sap must be collected so it doesn’t become too warm in the bucket and spoil. We fill our 50 gallon stainless steel boiler pan until it contains at least 40 gallons of sap, enough to make a gallon of syrup. The sap in the photo below has been boiled down for about half a day and is acquiring the distinctive color of maple syrup.
Our evaporator is very simple: a pan set on a fire box. My brother, Bryce, welded the box for us to specially fit the pan. We use gasket to seal the juncture so no smoke escapes. Smoke near the sap creates a smoky taste in the syrup that most people do not appreciate.
To speed the evaporation process, we cover the pan with a stainless lid specially made to fit. The lid is domed so precipitation and contaminants run off the top, and condensation from the boiling sap flows to the outside edges and drips off. When the steam is heavy, the dripping from the edge of the lid is constant.
We use stacks of galvanized joist ties to lift the top off the pan so steam can escape. Covering the pan makes the sap boil down twice as fast as when it is open. When the fire is roaring, the sap reaches a rolling boil and the steam pours out. We can boil down 40-plus gallons of sap in two days. If the sap is running well and we need storage room, we have some plastic garbage cans lined with food safe plastic can liners. We bury the cans in the snow and cover them with a tarp to keep the sap cool. This natural refrigerator works very well and lasts for the entire season. The storage cans are under the blue tarp behind my husband, Tim. The firewood, mostly dry pine from fallen trees and limbs and waste wood such as limbs from firewood trees, is stacked each year, mostly by Tim. Lots of dry, resinous pine, a mix of large and small pieces, makes a hot fire. We have been know to roast hot dogs and marshmallows over the fire for lunch during a day of sap boiling.
Care must be taken as the sap nears the bottom on the pan. Too hot a fire can reduce the sap to syrup, then maple taffy and finally a burned mess. Once the sap has boiled down to about four gallons on the bottom of the evaporator pan, it is time to draw it off. The sap is carried to the house and finished on the electric stove in the kitchen. Trying to finish the syrup in the woods is not practical. The heat can’t be controlled well enough and the environment is not clean enough for bottling the finished product.
The sap is strained twice through special felt-like filters, once before the final boil in the kitchen and again to remove the maple sand before bottling the syrup. Maple sand is a precipitate of minerals that forms when the sap becomes concentrated enough. It must be removed or it will form a sludge on the bottom of the syrup containers.
The four gallons of near-syrup carried up from the sugar bush take a few hours to reduce down in the house. Sap becomes syrup when it reaches a temperature of 219 degrees F. We cook ours a little longer to make it nice and thick, the way we like it. As the sap nears syrup stage the pot must be watched. When it becomes syrup, it can easily boil up, expanding to several times its volume, to overflow and make a sticky mess of wasted effort. Not to mention wasted maple syrup! The finished syrup is strained, then ladled into sterile jars. Syrup must be maintained at a temperature of at least 180 degrees F while it is bottled to kill any mold spores or bacteria in the air. Well canned syrup will keep for years.
The weather has now gone very warm. I pulled all the maple taps last night and we are boiling down our second and final gallon of syrup. Not bad for a syrup season that lasted about one week. The maples are starting to bud, the snow is disappearing fast, and soon we will have all the rest of the spring work to keep us busy.