The Bigleaf Maple (Acer macrophyllum) is the most common maple in the Pacific Northwest and you probably have one or more in your neighborhood or even your own backyard. The sweetest sap runs in January and February although you can harvest from November through early March, but only once the leaves are off the tree and before the buds open. Sugar content of the sap averages only 2% which means you'll need 6 gallons to make 1 pint of syrup. Don't despair, you can also use the "maple water" (sap) to boil rice, in soups, breads, teas or how about boiling it down just enough to concentrate the sweet flavor and serve it as shaved ice? The sap is nutritious containing amino acids, vitamins and many trace minerals.
So what size of tree produce the best? A trunk diameter should be between 4” and 18” and the bark should be somewhat smooth. The trees I tapped were much larger than this so I was able to put two taps in each. Reportedly the best run comes from the suckers or shoots of trees that have been cut down. These work well for tapping as they have a large established root system and you can use a big bucket to collect from several stems using plastic spiles and tubing.
Drill 2 – 2 1⁄2′′ deep hole at a slight upward angle. If you drill too deep you may hit heartwood. Don't fret, you are not hurting the tree. It will heal the wound. You may find that your holes will dry up. You can drill a new hole nearby with no ill effect. After the spile is removed it will take about a year for the hole to scar over. Drive the spile in place gently with a hammer to prevent leakage. Then hang your bucket over the spile. Be sure to use a lid as baby slugs and other insects will crawl inside.
Store sap in a cool place or freeze it boiling down every few days depending on harvest amounts. Strain the hot finished syrup through an unbleached cotton towel to remove the “sugar sand.” The sap can then be poured into hot sterile jars and sealed or frozen. Low sugar content can make the syrup spoil but syrup that grows mold can be filtered and re- boiled with no damage to the flavor.