One of the only things to get me through this winter has been the now steady drip, drip, drip of sap into the sap bags. We're getting a bit more than a gallon a day from each tree as long as the temps go below freezing at night. Some days, we get more.
It's the freeze/thaw cycle that pumps the sap through the tree.
I let the sap bag get about 1/3 full and then empty it. We've had it spill because it gets so full and I don't want to lose a single drop. This week I've been emptying a couple of times a day - and one day we emptied three times. We got close to 2 gallons that day.
I'm so looking forward to the boil.