236 TECHNICAL BULLETIN 13 



present in the juice and with due regard to tlie hydrogen ion concentration 

 of the juice, optimum yield and quality of the jelly resulted and there was 

 no great variation in either jelly yield or quality. The 3:4 ratio of fruit to 

 extraction water, though giving maximum yields of juice, solids, and jelly 

 was found to be impracticable, because of the dilution of the resultant juice, 

 the greater fuel consumption in concentration, and the loss of jelly quality. 



Acidity of Apple Jellies 



The total titratable acidity as well as hydrogen ion concentration was de- 

 termined on all jellies. These data are summarized in Table 6. The total 

 acidity calculated as malic acid varied from 0.22 per cent in Mcintosh to 

 0.66 per cent in Red Siberian Crab. The pH value varied between 3.62 for 

 the 1925 crop of Baldwins and 3.20 for Red Astrachans. Inasmuch as jelly 

 yields were dependent to some degree on the pH of the juice, the lower this 

 value, the better was the yield of jelly. Most people prefer an acid or sub- 

 acid jelly, hence those varieties possessing high total acidity and hydrogen 

 ion concentration are to be preferred for use in jelly making. 



Sugar Content of Jellies. 



The sugar content of all jellies was determined by the Abbe refractometer. 

 On 101 samples of Baldwin jellies the sugar ranged from 61 to 72 per cent 

 with an average of 65 per cent for jellies classed as marketaljle, i. e.. Grade 

 1 or 2. The soft jellies very often contained over 70 per cent of sugar and 

 crystallized badly during storage. The sugar content of high grade jellies 

 made from Red Astrachan, Crab Apple, Rhode Island Greening, Winesap and 

 King David averaged 67.5 per cent. Mcintosh and Wealthy gave jellies 

 with a sugar content of approximately 65.5 per cent. 



Most directions or recipes for making jellies proportion the amount of 

 added sugar to the juice. This is satisfactory only when extractions are made 

 in exactly the same way, i. e., time and temperature of extraction, number 

 of successive extractions, ratio of fruit to water and still other factors must 

 remain nearly constant. Othewise there is danger of using too little or too 

 much sugar for maximum yields of good quality jelly. 



It is far better to proportion the added sugar to the weight of fruit origi- 

 nally taken, viz., pound for pound or some other ratio as experience may 

 indicate. This basis is much more scientific and makes for a better product. 

 Each apple variety differs from the other in suitability for jelly manufacture 

 (Tables 10 and 11.) For example, Red Astrachan, King David and Red 

 Siberian Crab produce highly colored and well flavored jellies. Other va- 

 rieties such as Greening give very light colored jellies; still others are low 

 in acidity, or give jellies which are cloudy or of poor consistency. The va- 

 riety is important if a product possessing certain known qualities is desired. 

 On the other hand nearly all varieties will yield a fair amount of good edible 

 jelly. 



Maturity is important, because in apples past their prime, the pectin un- 

 dergoes deterioration and produces not only a low yield but a poor quality 

 jelly as well. Seasonal differences in varieties (Table 13) do not appear to 

 be particularly significant. 



By consulting Table 14, it is possible to estimate the yield of apple jelly 

 that may be obtained from a unit weight of apples providing the same manu- 

 facturing procedure is followed. Since approximately 67.5 per cent of the 



