16 MASS. EXPERIMENT STATION BULLETIN 336 



juice is probably due to some of the decomposition products of pectin, such as 

 pectic acid, which are formed by the action of Pectinol, but is so slight as to be 

 of doubtful significance. Some of the slight decrease in the gelatin-tannin 

 treated juice might be ascribed to the loss of tannin or tannic acid. 



The clarified ciders had a lower specific gravity and Brix value than the un- 

 treated ciders, Pectinol causing more of a decrease in both instances than 

 gelatin-tannin. Loss of pectin would be one factor responsible for the decrease 

 in specific gravity and Brix value, but more important would be the small loss 

 in sugar content through fermentation during the required settling period. 



The average content of tannin and coloring matter was lowered more than 

 a half by treatment with gelatin-tannin, but only a little less than a third by 

 the Pectinol treatment. Since the gelatin-tannin treated cider is much lighter 

 in color than the Pectinol treated, it is not surprising to find such a variation 

 in the amount of tannin and coloring matter as determined chemically. 



Ciders clarified with Pectinol had a higher ash content than did the gelatin- 

 tannin treated juices. 



FILTRATION 



Much of the cider produced is not filtered, but experience shows that a clear 

 cider is much preferred by the consumer. Small cider manufacturers often press 

 the cider and store it in tanks overnight to settle. By siphoning the cider from 

 the upper levels of the tanks, a fairly clear product can be obtained. Too long 

 storage must be avoided or fermentation will occur and defeat the purpose of 

 the tank clarification. In this state the semi-clarified juice may be filtered 

 through a cloth filter or even through a filter press though a filter-aid is necessary 

 if the latter is used. This process is best carried on in cool weather. 



The muddy residue can be used for vinegar stock. 



Muslin Tube Filter 



A simple homemade filter has been developed at Michigan State College by 

 Hickok and Marshall (17.) (See Fig. 6.) Their description of the muslin 

 tube fruit juice filter and its operation follows: 



The set-up for performing the filtering operation consists of three 

 principal parts: 



1. A mixing and supply tank. 



2. Elevation of the supply tank to provide a pressure head on filter 

 unit. 



3. The collecting or filtering unit. 



The collecting unit is the novel and most essential part of the outfit. 

 It is a long, slender, cloth tube, closed at one end, with the other end 

 connected to a rubber hose extending from the supply tank. This tube 

 is laid in a horizontal position in a trough. When the mixture of cider and 

 filter aid is fed into the closed tube, the pressure swells the tube to its 

 full dimensions. The cider is forced out rather uniformly over the entire 

 surface of the tube and the filter aid forms a cake of uniform thickness 

 on the inside. The trough is given a slight slope so that the clear juice 

 runs out of one end into a receptacle. 



The cloth tube is made of unbleached muslin, sewed to give a diameter 

 of approximately three inches. A tube of a larger diameter will not 

 support the filter cake satisfactorily and subsequent cracking and break- 

 ing of the cake may cause cloudiness in the filtered cider. A tube one 

 yard long is most convenient. It cleans easily, coats evenly in a short 

 time, and is the usual cloth width sold. It is recommended that both ends 

 of the tube be left open to facilitate cleaning. In use, the dead end 

 should be folded back, carefully gathered and tied, preferably with a 

 single miller's knot. 



