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 may be 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. 



-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. 



