106 



served to strain or filter the cider almost perfectly. This was observed 

 in an English factory where the must was fermented in open " keeves," 

 the head being skimmed off until active fermentation had subsided, 

 and the product being then run through this filter and put into casks 

 for ripening. This apparatus does good work, but the cider is much 

 exposed to the air. 



The cellulose power filter. Some of the English makers have come 

 to use the German filter shown in figure 2-i. This is made by Otto 

 Fromme at Frankfort, and is the best device observed. It is, how- 

 ever, costly, and a force pump is required to drive the liquid 

 through the filter, or the liquid must be drawn from some height in 

 order to give the necessary pressure. This is also a wood pulp or 

 cellulose filter. The pulp is arranged between perforated disks, and 

 the machine permits of dismounting and washing the parts and the 

 pulp at will. In some English factories attempts were made to filter 



FIG. 24. Cellulose power filter used in Germany. 



the fresh juice with this machine, but this generally resulted in fail- 

 ure, and besides was very wearing on the apparatus. Fresh apple 

 must is very difficult to filter because of the pectose or mucilaginous 

 substances it contains. The use of any of the above filters does not 

 appear to be practicable except when the must has been fairly well 

 fermented, and has freed itself in this manner of a large part of the 

 parenchymatous tissues and albuminous matters present therein. 



Asbestos sack filter. The French use a filter (fig. 25) which they 

 claim will remove all insoluble matters from the fresh must, and leave 

 it clear and limpid as it goes into the cask. No demonstration of this 

 was seen, but this filter (Filtre Maignen) is much used in France, 

 and appears to be a good, cheap filter. It is made from asbestos. 

 A fairly closely woven asbestos sack, 10 or 12 inches in diameter and 

 of any desired length, is tied tightly at one end; then in the bottom of 

 this is placed an openwork disk, and a string is tied above the same so 

 as to nearly draw the sides of the sack together; above this is placed 

 a second disk; and so on until the filter sack is filled. The open end 



