Making Maple Syrup in the City

By Amy Galblum

I am starting my third year of making maple syrup in Roslindale from several 100+-year-old sugar maple trees surrounding my house. I got started with 4 maple taps (about $3.50 each), a covered metal bucket ($22) and a “how-to” book on backyard sugaring.

Maple sugaring is pretty simple. Sap runs in maple trees in the spring when the days begin to warm up. Sugaring starts when the daytime temperatures are above freezing (32 degrees) and night temperatures dip below freezing. That first warm day is the signal to head outside with a drill, taps and a hammer.

With a 3-quarter-inch drill bit, I drilled holes through the bark about an inch deep and gently hammered a tap into each hole. Large trees can support 3 or 4 taps but smaller trees are better off with just one. Clear almost tasteless sap begins running just as soon as the tap is set.

I have one traditional, covered metal bucket and also use clean one-gallon plastic (milk) jugs with a quarter sized hole cut out near the top. The milk jugs are cheap and almost preferable because the amount of sap collected can be seen from the kitchen window, and they can be swapped out – full ones removed and empty ones hung up.

Maple sap generally runs for about 6-8 weeks and stops when the night temperatures warm up so there is no longer an overnight freeze. At that point taps should be pulled out.

Processing the sap over the weeks it is running is constant. My large trees produce almost a gallon of sap from each tap every day on a warm day. Sap can spoil like milk so it must be processed promptly or kept cold. The first year I was able to stash gallon jugs of sap in a snow-bank on my porch on days when I didn’t have time to boil it down, but when there is no snow, room must be found in the refrigerator.

It takes approximately 40 gallons of sap to make a gallon of syrup and this varies from year to year as the sugar content is not constant. With my crude calculations, I found it was closer to 35 gallons of sap per gallon of syrup.

The process of getting from sap to syrup is just boiling. I use a roasting pan stretched over 2 burners, and a large stockpot. There is not much actual work involved in boiling the sap down, just adding more sap as it boils off, and skimming off foam every once in a while. It creates a lot of steam which is why commercial sugaring is done out of doors in what New Englanders call a “sugar shack.” A good stove hood fan is a necessity for boiling indoors.

When the supply of sap is done and the boiling has gone on for a while, the syrup starts to take on a caramel color. At that point it needs to be watched more closely and is best transferred to a small saucepan. As it gets close to the syrup stage, it will begin boiling in little bubbles instead of a rolling boil like water, and will easily boil over if not watched carefully. A candy thermometer is helpful to determine when the syrup is done. Water boils at 212, and maple syrup is ready at 219 (and this of course varies depending on altitude). Five gallons of sap will produce about a pint of syrup in 4 or 5 hours.

The last step is to strain the finished syrup through a few layers of cheesecloth into clean pint jars. Full Jars will seal if they are laid on their sides with the hot syrup covering the lid.