12 MAPLE-SAP SIRUP. 



and pieces of bark. True, the insoluble substances may be removed 

 when the sap is poured into the container by passing it through a 

 small mesh sieve, as is the usual practice, but the foreign material 

 that has been dissolved remains. The snow and rain dilute the sap 

 and hence more evaporation is necessary, while the washings of the 

 trees always darken the sirup and also affect the flavor. It is claimed 

 by some that the sap sours sooner in a covered bucket than in an 

 open one. This may be true if the buckets are not kept clean, but 

 if they are washed occasionally and the sap is collected often enough 

 there will be little or no souring. 



As the sap is a dilute solution of sugar with a little mineral and 

 some nitrogenous matter, it forms an excellent medium for bacterial 

 growth even under the most cleanly conditions, and when left in the 

 bucket during a warm day there is a tendency for souring to take 

 place; if left for a second day, it will surely sour. Freezing stops the 

 souring temporarily, but it continues when the sap thaws. For this 

 reason the buckets should be emptied as often as possible, at least 

 once or twice a day. Another important point is to use an evapora- 

 tion apparatus that is large enough to handle the sap of the "bush" 

 at its maximum output. If the collected sap can be boiled imme- 

 diately the danger of fermentation is largely avoided and hence a 

 good colored and well flavored sirup is assured. 



The best care should also be taken of the collecting apparatus. 

 Wooden tanks should be painted and all collecting utensils often and 

 thoroughly washed. Fine meshed sieves should always be kept over 

 tanks, and these may be supplemented by cloth to prevent the entrance 

 of fine foreign material that darkens the sirup. 



At the boiling house the greatest care should be used. The arrange- 

 ment should be such that the sap may be kept in a cool, clean tank, 

 preferably outside of the house, and handled as quickly as possible. 

 Boiling in the open, under no shelter, is not good practice, as the dirt 

 can enter the sap freely, but equally unclean is the product made in 

 a house with the ash pit uninclosed and a smoky atmosphere due to 

 a poor chimney. In either case, if much dirt is present both the 

 flavor and the color of the sirup will be changed. The use of iron 

 kettles, iron pans, or modern evaporators in boiling are variations 

 that also influence the color of the product. 



The lightest-colored sirup is produced when the sap is boiled very 

 fast without the addition of fresh sap. This holds good for all kinds 

 of sirup and sugar making, whether from sugar cane, sorghum, the 

 sugar beet, or the maple tree. To repeat the process of boiling down 

 a weak sugar solution to a thick sirup, thinning again with fresh sap 

 or juice, and reboiling always leads to darkened products. Theo- 

 retically, the sap should run in a constant thin layer over the heating 

 surface, be concentrated, and then run out to the container in order 



