Micro-organisms of Maple Sap t61 



The average moisture content for the entire i_>X samples 

 is 34.63%. This is practically the moisture percentage of a 

 standard eleven-pound to the gallon sirup. 



The average sucrose figures 61.44%, anc l tne invert sugar 

 percentage, l.6o%, agree quite closely with the averages, 62.649? 

 and 1.49%, secured by Bryan in an examination of 395 samples 

 from all parts of the United States where maple products are 

 made. 



The average total ash figure on a moisture free basis is 

 0.93%, and extremes are 0.74 and 1.44%. The minimum figures 

 occur in the "last run, sour" group and include considerable num- 

 ber of buddy sap samples. 



The average insoluble ash percentage is well over the stand- 

 ard in every group, the minimum being 0.29, the maximum 1.01, 

 and the average 0.59%. 



The malic acid value is likewise above the standard limit, 

 with a minimum of 0.71, a maximum of 1.21, and an average of 

 0.90%. 



The grand average for the 128 samples secured in the three 

 sugar seasons is in every particular typical of pure maple sirup, 

 and would of course more nearly represent the output of thai 

 particular sugar orchard than would any single sample or minor 

 group of samples. 



INVF.RT SUGAR CONTENT OF MAPLE SIRUP 



The invert sugar present in the sirups obtained in this in- 

 vestigation shows extremes, calculated to a moisture-free basis, 

 of 0.12 and 28.35%. Invert sugar results from the hydrolysis 

 or inversion of sucrose, caused by yeasts, molds, bacteria, acids, 

 etc. Thirty-two sirups, or a quarter part of the entire number of 

 samples, carried less than 0.60% of invert sugar on a moisture- 

 free basis, while 57 samples, or 45%, contained less than 1%. 

 Hence it seems fair to conclude that an invert sugar content in 

 maple sirup of much more than 1% can only be due to careless 

 methods in handling or to delay in boiling the sap, or to the sub- 

 sequent fermentation of the finished product. 



