By-products of the Northern Woodlot 231 



on the bottom and sides of the kettle or pans. This is a 

 lime formation, and if floating, it maybe removed by strain- 

 ing through cheesecloth, or by allowing it to settle and 

 later draw off the clear sirup. In sirup-making, the 

 boiling should be completed at the proper time. This is 



FIG. 52. Boiling down the sap in kettles in the woods. 



determined by testing in various ways. If the sirup is 

 too thin, it has a tendency to sour ; if too thick, it will 

 crystallize and form sugar. When properly made, a 

 gallon should weigh eleven pounds. This is the standard 

 weight of a gallon. After a little experience, the maker can 

 very readily judge the density by the way the bubbles 

 break on the surface of the boiling sirup or by the way it 

 pours from a spoon. A safer way is to test with a ther- 

 mometer. Sirup that boils from 217 to 219 F. is at the 

 correct density and will weigh about eleven pounds a gal- 

 lon. A safer plan is to weigh a gallon of the cool sirup. 



