The Maple Syrup Makers program at Robert J. Lister Academy in Portsmouth teaches students about the science behind syrup-making in their own on-site sugar shack, all led by teacher Christine Stilwell.

Depending on the line, it’s 40 to 120 bottles per minute. Sweet maple syrup. Sweet profit. Now exposed. The executive has his best game face on but a trade war is at his doorstep. U.S. President ...