APPLE BY-PRODUCTS AS STOCK FOODS. 5 
should yield 160 gallons of juice (33 per cent of pomace) if well 
pressed. He recommends a pressure of not less than 500 pounds 
per square inch. The pressure commonly recommended for factory 
practice for the larger modern cider presses is 800 pounds per 
square inch of " cheese." 
Reports from a large number of cider mills in the United States 
show that the yield of pomace is about 30 per cent, on the average, 
based on a water content of 80 per cent. 4 In American mills the 
pomace dry matter constitutes about 6 per cent of the weight of the 
apples crushed. These, of course, are only rough estimates. The 
proportion of pomace produced depends upon the quality of the 
fruit and the type of mill. 
The estimates of the total tonnage of apple pomace produced by 
commercial operators in an average year is based on reports from 
cider manufacturers. It is assumed that 15,000,000 48-pound 
bushels of apples are pressed for cider each year 5 in the New El g- 
land States, New York, New Jersey, Pennsylvania, Virginia, Wesl 
Virginia, Ohio, and Michigan, and that 7,500,000 bushels are pressed 
in the rest of the country, making a total of 22,500,000 bushels. This 
would give 162,000 tons of pomace containing 80 per cent of mois- 
ture. In addition, many thousands of tons of pomace are produced 
on the farms. Fippin (66) states that 5,250,000 gallons of cider 
were made on New York farms in 1909, an increase of 1,000,000 gal- 
lons over the average yearly production for the preceding decade. 
This quantity of cider would result in the production of over 9,000 
tons of moist pomace on the farms of New York alone. 
MANUFACTURE OF DRIED APPLE BY-PRODUCTS. 
APPLE POMACE. 
In 1916 (139) one of the larger mills in England which dried 
apple pomace on the commercial scale used rotary dryers of German 
make, such as are employed for drying exhausted beet cosettes. The 
technique of drying apple pomace and similar products is discussed 
in most of the recent French papers reviewed. Those of Vernon 
(136), Warcollier (188, 139), and Tanvez (131) include details of 
value. La Cidrerie (1ST) gives the following description of the op- 
eration of a Vernon rotary drying system. 
Three units of varying capacity, capable of handling 770, 1,210, 
and 1,980 pounds, respectively, of fresh pomace per hour, are em- 
ployed. Three workmen (an engineer, a man to feed the dryer, and 
one to sack and weigh the finished product) are needed. The three 
units require 4, 6, and 8 horsepower, respectively. From 40 to 50 
pounds of coal is used in the production of each 100 pounds of dried 
pomace. On this basis the fuel cost in the United States per ton 
of dried pomace would be between $3 and $4. Rotary kilns seem to 
have been generally adopted. 
*The average moisture content of fresh apple pomace from 81 American determinations 
is 80 per cent; from 15 English determinations, 71. •> per cent; from 8 French deter- 
minations, 7'.».t; per cent ; and from "> German determinations, 75.2 per cenl : :m average 
of 78.6 per cent Cor 109 determinations. Many of the determinations included, how 
were made before efficient presses were the rule. The average moisture content of Ameri- 
can twice-pressed pomace probably is to-day almost 75 per cent. 
B The pressing season in northeastern United states is from September to December, 
inclusive. 
