4. Secondary concentration techniques by boiling at atmospheric pressure

In the past, raw maple sap was concentrated in large iron cauldrons in the middle of the woods. Until the 18th century, maple syrup was produced in small quantities for a family and a few friends, the sugar of the poor who couldn't afford the precious and expensive cane sugar. The first maple syrup evaporator was invented and patented by two Americans, the Samll brothers, in 1889, and quickly won out over iron cauldrons, ushering in an era of highly sophisticated, high-performance evaporators as we know them today.