APPLE CIDER 3 



Specific Gravity 



The determination of specific gravity was made using a hydrometer at a 

 temperature of 21° C. (70° F.). The figure given in the table represents the 

 number of times heavier the cider is than an equal volume of water when both 

 are measured at a standard temperature. Specific gravity may be used as an 

 approximate method of determining the arHount' of alcohol formed during the 

 ^fprj gipritat.irQof cider.^ _A nine-point drop on the hydrometer scale is equal to 

 approximately 1 percent of alcohol by volume, so that a sweet cider with a 

 specfic gravity of 1.050 at the start of the fermentation would have to be fer- 

 mented to 1.041 to get a 1 percent alcoholic content by volume. 



As will be seen from Table 1, the highest specific gravity was found in the 

 Russet and crab-apple ciders, the lowest in the Mcintosh and Wealthy ciders. 



Degrees Brix 



The Balling or Brix test indicates roughly the percentage of sugar in the 

 juice, or, more exactly, the concentration of a sucrose solution of the same 

 density as the juice being tested. 



The determination was made with a hydrometer of the same type as that 

 used for the specific gravity determination, the difference being that the Brix 

 hydrometer has a scale calibrated in degrees from 0° to 30° or 30° to 60°, de- 

 pending on the sugar concentration of the liquid to be measured. The actual 

 sugar content is usually 1.5 to 2 percent less than the degrees Brix as this 

 reading is influenced by other soluble solid material in the juice such as 

 minerals, acids, pectin, proteins, etc. However, the determination is very 

 simple and rapid and is one that any cider manufacturer will find helpful. The 

 Russet and crab-apple ciders had the highest Brix reading of all the varieties 

 tested. 



The Brix reading may also be used to estimate the percentage of alcohol 

 formed during fermentation. A decrease of one degree on the Brix scale indi- 

 cates that approximately one half of one percent by weight (0.5%) of alcohol 

 has been formed. For example, if the Brix reading was 12° at the start of the 

 fermentation and if at the end of a week the reading had dropped to 6°, the 

 alcohol content of the cider would be roughly 3 percent. 



pH Determination 



Measurement of pH was made with a quinhydrone electrode during the 1934 

 season and by the colorimetric method during the 1933 season. This determin- 

 ation is not one that the average cider maker will use, but the pH value is an 

 important factor to be considered in blending ciders. The reason for this is 

 that two ciders might have the same total acid content but because of other 

 constituents in the juice, the "active" acidity or pH might be different. It is 

 the "active" acidity which determines the relative sourness or acid taste of a 

 product. A low pH value indicates a high degree of "active" acidity and vice 

 versa 



The results in Table 1 indicate that the pH varies somewhat from season to 

 season and that there is also considerable difference between varieties. Of the 

 ciders made during the 1933 season Mcintosh had the lowest pH and Ben Davis 

 and King the highest. Cider from the two latter varieties also had the highest 

 pH in 1934, while Russet and Wealthy had the lowest. 



