Some of our maples have started to produce sap which we will soon start boiling down into the Nectar of the North aka Pure Maple Syrup! This flow of sap will continue as long as we have air temperatures cycling below and above freezing.
When the trees thaw initially they take up water along with the stored sugars they had deposited last fall. As the tree refreezes the water it has taken up expands and creates a positive pressure within that will push the sap out the taps. Eventually the pressure will equalize if the tree doesn’t freeze up again and the sap flow will stop, but each time the tree refreezes pressure will be regained. This process will last 4-6 weeks. By that time the temperatures will stop dipping below freezing or the sap will start to turn off-flavored due to the leaf and flower buds breaking open.
This kind of pressure build up during sap flow is found in only a few types of trees. Thankfully, God has designed the maple in this way so that we can harvest the sugars in the sap and boil them down into a delectable syrup!
One final parting fact: The Box Elder Tree (Acer negundo) is part of the maple family and can be tapped for maple syrup.