452 Bulletin 167 



Group 15. Inoculated with pink yeast; burned control. 

 These two samples, while grouped together, bear no relation to • 

 each other. The pink yeasts are not as common as are the red 

 and gray yeasts previously mentioned, but, like them, are en- 

 countered late in the season. The effect on sirup made from 

 sap inoculated with pink yeast is shown in No. 98, which may 

 be considered a typical yeast sirup. Both flavor and color were 

 impaired, particularly the former. The sirup ranked poor in 

 quality and, while grading commercially as No. 2, showed a 

 color depreciation of 6 points. This organism exerted a marked 

 inverting action on the sucrose, but the other results, including 

 those for ash and malic acid value, are normal in spite of the 

 increased concentration, indicated by the low moisture content 

 of 29.26%. 



The burned sample. No. 74, listed in this table, was a control 

 on the fluorescent and spore-bearer series shown in table 12. 

 Tt was slightly burned, so that the flavor and color were seri- 

 ously affected. The burning had but little if any effect on the 

 invert sugar percentage, as only 0.70$ calculated to the mois- 

 ture free basis was found. 



