Micro-organisms of Maple Sap * ; >T 



The moisture content varied from 30.94 to 41.50 and aver 



aged 35-6o%. 



The sucrose averaged 57.78% with extremes of 45.49 and 

 67.05%. The low figure which was obtained on No. 109 is due 

 mainly to the high invert sugar content of [9.15%, equivaleni 

 on the moisture free material to 28.35$ ■ This was the largest 

 invert sugar percentage obtained with any of the samples ex- 

 amined. Reference to the field notes shows that the inoculating 

 organism multiplied rapidly and was an acid producer, a con- 

 dition which doubtless served to hasten the sucrose inversion. 



The total ash on the moisture free basis shows a deficiency 

 in two cases, Nos. no and 115. The insoluble ash is also low in 

 No. 115. The malic acid value meets the standard in every case. 



Group 8. Inoculated with fluorescent bacteria. These or- 

 ganisms occur more commonly in maple sap than do any of the 

 others used in this work. They grow well at low temperatures and 

 hence should be guarded against early in the season. They im- 

 pair the flavor somewhat although not as seriously as several 

 other groups. Nine of the 22 samples reported were graded 

 as No. 2 in flavor, indicative of a good sirup, six as No. 3, a good 

 medium sirup, while seven were classed as No. 4, corresponding 

 to poor. The color was seriouly injured by this fluorescent 

 group. They cause but little if any inversion of the sucrose 

 and never produce the objectionable yeasty taste so characteris- 

 tic of many contaminated sirups. 



