I left for parts unknown in deep winter, with ice rain and other assorted pellets and sticky things descending from on high almost daily, followed by a thick blanket of snow. From across the pond, I confess to being only mildly perturbed to not be part of the daily efforts to deal with it all — returning after two weeks to a white, white, and cold world.

The sun’s warmth on my back on that first 15 degree day home foretold major changes on a bog bright with a thousand winter suns. And now we’re on the down slope towards spring. Though the bog is covered in snow and ice, anything not-white is making a deep dent. Water shines in luscious black against white, glistening snow. We’re sugaring.

Crossing he bog I worry the forecast I have just read — without freezing nights the sap won’t flow in the sugar maples and no frost for three nights.  Does the beginning also spell the end of the sugar season this year?

Maple trees are very much in the moment. We have rules of thumb about when sap does and does not flow. The sap starts flowing when it gets warm in the day and freezes at night, and stops when it gets cold again during the day or stays warm in the night. This seesaw we have plenty of in New England so we get good sap flow. But the trees don’t seem to obey those rules half the time. They work with physical laws more complex than is known in our simplistic philosophies. Why is there sap in the bucket on a warm morning?

A tree is a miracle of physics and chemistry. Pressure and suction, tells the Cornell farm extension website, determine sap flow. And from what I read the maple tree is like a bottle of fizzy. With warmth, pressure develops in the tree when the cells in the sapwood (the outer layer of wood) create carbon dioxide as they grow. You drill, sap flows out. With cold, usually at night, the carbon dioxide contracts and suction sets up that pulls water into the tree through the roots, picking up for tree building blocks sugar stored last year along the way. If the nights don’t cool down, the sap may keep running. But the tree needs to drink to produce sap, and drinking it does only when it is cold. Without, the tree runs low on sap — then it’s time to wait for another period of cold. These trees need New England as much as New England needs these trees.

But right now it is July in February, boiling sap an après-ski type activity, as we lounge in lawn chairs soaking up the sun, listening to the wind high in the trees, the drip-drip of snow off the eaves, crows in yonder stand of birches, and geese negotiating possession of the bog down the hill. When asked, the carpenter reports he’s pleasantly bored watching so the kettles do not boil over. Maple sap is syrup when liquid gold roils at 7 degrees Fahrenheit over the boiling point of water. Just now, on our thermometer, at 1358 feet altitude, that’s 115.4 degrees.

When done in a kettle over an open fire, reducing 12 gallons of exceptionally sweet sap to a quart and a half of syrup takes one person almost a day of physical labor to achieve. If there’s another for logistical support and to finish the syrup on the stove inside.

The morning brings rain and fog all around, followed by more checking of buckets on snowshoes in 60-degree weather. No such luck. In three days, eighteen inches of snow have been reduced to six of rotting ice. The pump in the basement is busy. Tonight it’ll freeze, and more sap will flow. It’ll work as long as we have New England weather here in New England, I reckon.