Pure maple syrup is a beautiful thing, sweet, with complex flavors, and it can only come from boiling the sap from a tree, a time-consuming process dependent on the weather. This year was off to a slow start with a warm January and “stone cold” February, according to Michael Bryant of Hilltop Boilers in Newfield. But the sap is running in March, and the coming week should be a good one if it doesn’t get too warm. Maine Maple Sunday is March 28, but this year the 38th annual event will have adjusted hours and options because of the coronavirus pandemic. Press Herald photographers visited some southern Maine makers busy producing syrup last week.