How to Cook Down Maple Sap

Sugar maple pail on tree

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Producing old-fashioned artisanal foods from scratch is an appealing prospect, but taking up beekeeping or curing your own bacon can be a major undertaking. Making your own maple syrup is a much easier project, requiring only a modest investment in time and equipment. All you need are a few sugar maples or red maples, at least 10 to 12 inches in diameter, and some taps and buckets to collect the sap. The time-consuming part of the job is cooking down that sap into syrup.

Pour the raw sap through several layers of cheesecloth to strain out any twigs, leaf mold, insect, bark fragments or other debris that might have found its way into your buckets. It takes approximately 10 gallons of sap to make a single quart of syrup, so you'll need several buckets to hold the unstrained and strained sap.

Place your largest pot on your stove, or better yet on an outdoor burner. You'll need to boil away about 40 quarts of steam to get one of syrup, and that's a lot of steam to pump into the air in your house. If you must boil the sap indoors, keep your range hood's fan on and -- if possible -- open the windows. Fill the pot with sap, and bring it to a low boil.

Boil the sap continuously, keeping a spatter screen over the top of the pot to prevent insects or dust from falling in. Whenever the level of sap in your pot drops by about a third, top it up with fresh sap.

Continue topping up the pot until you've added all your raw sap. Until this point the process requires little hands-on attention, but once the pot contains the last of your sap you must start monitoring it. As the sap approaches a syrup concentration, it will begin to foam and might boil over.

Test the syrup with a hydrometer, if you own one or can borrow it. It's a specialized device that tells you the concentration of sugar in your syrup, with 67 percent being ideal. If you don't have a hydrometer, use a good-quality candy thermometer. Syrup at the right concentration boils at 7 degrees Fahrenheit higher than the boiling temperature of pure water, or 219 F at sea level.

Strain the syrup again, through cheesecloth or a commercial syrup filter. Pour it still hot -- at 180 F or higher -- into sterilized canning jars, and seal them immediately for storage.