19S Zessons in Fruit Growing. 



308. Filtration of cider. Cider to be used for drinl^iug- 

 should he filtered to remove particles of pulp, skin, seeds,, 

 etc., which give it a more or less turbid appearance, and 

 hasten fermentation. Large filters, for the rapid filtration 

 of cider, are on the market. Those in which the cider passes 

 through sand or clay are generally objectionable, as they 

 tend to impart an earthy flavor. 



A filter for a small amount of cider may be made as fol- 

 lows: bore a half-inch hole through the bottom of a wood 

 pail, and into this insert a short wood tube, projecting 

 downward. Then spread over the bottom of the pail, in- 

 side, circular pieces of clean-washed and dried cotton wad- 

 ding, cut to fit the pail, until, when pressed down, they 

 cover the bottom of the pail to the depth of 3 or 4 inches. 

 Cover the wadding with 2 or 3 inches of clean quartz peb- 

 bles about the size of a pigeon's egg, to keep it closelj^ 

 pressed. When clogged by use, the top layer of wadding 

 can be replaced by a new one, or all of the wadding can be 

 washed. Cider to be filtered should first be strained through 

 a very fine strainer. 



309. Cider vinegar. Dilute alcohol containing the vin- 

 egar ferment {Mycodenna aceti), exposed to the air at a. 

 suitable temperature, changes to acetic acid (vinegar), hence 

 cider, after developing alcohol, tends to become vinegar. 

 The more thorough the exposure of the cider to the air, and 

 the higher temperature, within certain limits, the more 

 rapidly does the change take place. About 95° F. is the 

 optimum temperature for economical results. Cider should 

 have a specific gravity of about 1.04 to make first-class vin- 

 egar; that of higher specific gravity may be diluted with 

 water or weaker cider; that of lower may be reinforced by 

 the addition of crude glucose. 



