MAPLE SIRUP PRODUCERS MANUAL 



37 



unit for pasteurizing flowing sap are available 

 (AS). 



Tanks must have easy access for cleaning 

 and repair. Workers must be extremely careful 

 when working in tanks that have only a man- 

 hole opening, so as to be sure they do not 

 exhaust the oxygen (ft-esh air) supply and suffo- 

 cate. 



Metal or glass-lined tanks such as surplus 

 milk tanks are ideal, since their walls are non- 

 porous and easy to clean. 



The walls and floor of masonry tanks should 

 be smooth and treated with a water-insoluble 

 coating to prevent places for microbes to lodge. 

 This surface-treating material must be one that 

 is approved by the U.S. Food and Drug Admin- 

 istration as safe for being in contact with food. 



The tanks should be washed with a detergent 

 after each run of sap and the detergent should 

 be completely removed from the tanks by using 

 at least three separate fresh-water rinses. 



There must be some indicating device inside 

 the evaporator house to show the level of sap in 

 the tank. This device may be simple sight glass 

 (a perpendicular glass tube connected to the 

 feed line of the evaporator), or it can be a float- 

 and-weight type, where a string attached to a 

 float in the tank is carried into the house, and a 

 weighted object is raised and lowered by means 

 of guides and pulleys as the level of the sap 

 varies. 



Figure 67. — A large underground concrete storage tank of 

 silo-type construction. 



If the feed line from the tank to the house is 

 aboveground, it too must be well insulated. 

 Numerous cases have been reported when the 

 sap line, even when in operation, has frozen 

 and shut off the supply of sap, with the result 

 that the pans were burned. 



Suinmarv' 



(1) Construct tanks with smooth, easy-to-clean 

 walls. 



(2) Locate tanks in a cool place — never inside a 

 warm evaporator house. 



(3) Cover tanks with clear plastic to utilize the 

 sterilizing action of sunlight. 



(4) Provide sterile lamps for large tanks with 

 opaque covers. 



(5) Provide an indicating device in the evapora- 

 tor house to show level of liquid in tank. 



(6) Keep tanks clean and sterile. 



EVAPORATOR HOUSE ON THE SAP-PRODUCING FARM 



Location 



Originally, most evaporator houses were lo- 

 cated near the center of the sugar grove to 

 shorten the distance the sap had to be hauled 

 (fig. 68). With the use of pipelines and large 

 collecting tanks, many producers today find it 

 more profitable to locate the evaporator house 



near the other farm buildings and close to a 

 traveled road (fig. 69). This offers many advan- 

 tages: (1) Water and electric power are availa- 

 ble; (2) laborious and time-consuming travel to 

 and from the evaporator house is eliminated; (3) 

 full family participation is encouraged; and (4) 

 the evaix)rator house is accessible to visitors 

 and potential customers. 



