Tin cans were used to store a variety of different foods, and in this case, it was used to package maple syrup for either personal use or to sell commercially. If the syrup was stored too long in the tin can, it would take on a slightly metallic flavor and therefore was not the best material to use for this purpose.
Maple syrup production is one of the few agricultural processes in North America that was not a European import but learned from the Native Americans in New England. Sap is typically collected from the Sugar, Red or Black maple, though it can be collected from other tree types. Northeastern North America is the most common area for maple syrup production, with Vermont, New York and Maine leading production in the U.S. Once the sap is collected, it must be boiled down to reduce the water content. It can require anywhere from 20-50 liters of sap to make one liter of syrup, depending on the sugar content of the sap. Each tree is capable of producing 35-50 liters of sap.