10 MAPLE-SAP SIRUP. 



CONDITIONS INFLUENCING COLOR AND FLAVOR. 



To just what chemical constituents maple sirup owes its particular 

 flavor is not known. It is attributed by Wiley a to an ether or an 

 aldehyde possessing a high boiling point, but nothing definite has 

 so far been discovered in the efforts made to isolate and identify this 

 substance. 



The true flavor of maple sirup when carefully made from the sap 

 under cleanly conditions is a very delicate one. The strong, 

 almost rank, taste noted in some cases and often thought to indicate 

 a richer maple product is due to a mixture of many flavors, the source 

 of which will be discussed later. A mild, delicate taste is usually 

 found in a light-colored sirup, and a strong flavor in a dark sirup, but 

 the converse is not always true. The aim of the maple sugar pro- 

 ducer to-day is to make a mild-flavored, light-colored sirup, since 

 these characteristics are considered as indicative of a pure maple sirup. 

 This requires careful manufacture and attention to details, though 

 the lightness of color depends also on the kind of tree tapped, the 

 manner of tapping, the method of collection, and the subsequent 

 handling. 



So far as can be learned, either from observation or by a survey of 

 the literature, no sirup made from the sap of the soft maple is of light 

 color or has a delicate taste, the tendency of this variety being to 

 give a reddish-brown sirup with a strong flavor, but in a great many 

 instances the soft maple is tapped early in the season, because its sap 

 flows much more freely at that time than that of the hard maple, 

 and by mixing the two the first sirup of the year can be produced 

 earlier than if only the hard maple were tapped. 



The flow of sap is by spells or runs, which generally occur in the 

 daytime. One or two pleasant, warm days after a freeze may make 

 the sap flow for some time, then a cold snap will stop the flow until 

 the warm weather returns. During the season there may be fifteen 

 or more runs, or there may be only two or three. The first of these 

 runs will produce the lightest sirup, while the last run, occurring at 

 about the time the buds are opening, very seldom produces either 

 light-colored sirup or one of fine flavor. The taste of the sirup from 

 the last run is popularly spoken of as "buddy." This "buddy" 

 flavor has been attributed to changes in the composition of the sap 

 at the time the young buds are opening. Edson 6 has recently demon- 

 strated that a buddy flavor may be caused by the development of 

 certain bacteria in the fresh sap, from the tap hole. He isolated and 

 studied some of these bacteria obtained from different "sour saps" in 

 1907, and in the following spring treated the first run of sap with 



oU. S. Dept. Agr., Bureau of Forestry Bui. 59, p. 47. 

 6 Vermont Agr. Exper. Sta. Bui. 151. 



