310 INTERNATIONAL CONGRESS OF VITICULTURE 



Four series of tests were made at Kearney and at Davis with Muscat 

 and Sultanina. The Muscats were gathered and dried at various degrees of 

 ripeness from 18.6 Bal. to 28.75 Bal., the Sultaninas from 20.5 Bal. to 

 25.6 Bal. The results were fairly concordant except in the case of the 

 Sultaninas where some of the raisins of the riper grapes were lost. The 

 concordant results were averaged and the drying ratio at various degrees of 

 ripeness calculated, as shown in the following table: 



Table II. Drying Ratio Grapes: Raisins (G/R). 

 (Calculated from experiment data.) 



Muscat. Sultanina. 



Bal. G/R Bal. G/R 



18 4.8 



19 4.5 



20 4.3 20 4.6 



21 4.1 21 4.3 



22 3.9 22 ....4.0 



23 3.7 23 3.8 



24 3.5 24 3.6 



25 3.4 



26 3.3 



27 3.2 



28 3.1 



Average.... 23 3.8 Average.... 22 4.06 



As very few of the raisins were lost in handling, these may be considered 

 as minimum drying ratios at the various percentages of sugar. Under ordi- 

 nary vineyard conditions the number indicating the ratios would be slightly 

 higher, as it is difficult to avoid some loss of material during the various 

 operations. The figures of the table include the weight of the stems accord- 

 ing to the usual custom. The Muscat shows a slightly lower drying ratio 

 than the Sultanina, owing probably to the presence of seeds in the former. 

 The difference would amount to about 16 pounds of raisins per ton of fresh 

 grapes in favor of the Muscat. 



As the tests showed that first-class raisins cannot be made from the 

 Muscats before they reach 25 Balling, or from the Sultaninas below 23 

 Balling, a drying ratio of 3.4 for the former and 3.8 for the latter should be 

 the maximum. Ratios above these figures indicate either insufficient matur- 

 ity of the grapes or losses of raisins in handling. If the gathering of the 

 grapes is commenced when this degree of ripeness is attained they will be 

 riper when the gathering is finished. The average drying ratio for the season 

 should, therefore, be lower. An average drying ratio of about 3.2 for Muscat 

 and of 3.6 for Sultanina may be considered excellent and indicating both 

 full ripeness of the grapes and little loss in handling. 



3. Quality. Variations in quality are much more difficult to estimate 

 than those of quantity. From the point of view of the consumer there is 

 no doubt that in all the tests the riper the grapes the higher the quality of 

 the raisins. This was the unanimous verdict of all to whom samples were 

 submitted. Samples were also submitted to expert raisin handlers and 

 buyers. The opinions thus obtained were not quite so unanimous. All 



