40 BULLETIN 1141. U. S. DEPAEIMEXT OE AGRICULTURE. 



possible to do perfect work if fruit is delivered so rapidly that two 

 or more apples are carried by a single cup. as the fruits can not then 

 move freely enough to turn into proper position for slicing before 

 reaching the knives. When it is desired to evaporate apples in 

 quarters or sixths they are run through machines which cut them 

 accordingly, the cutting being done in the opposite direction from 

 the slicing : that is. in -a direction parallel to the axis of the apple 

 instead of at right angles to it. 



If they are to be dried whole they are transferred from the bleacher 

 directly to the drying compartment without further treatment. 



EVAPORATING THE FRUIT. 



"When the fruit has been placed in the drying compartment of an 

 evaporator, of whatever type it may be. it has reached the most 

 critical stage in the whole process of evaporation, and it is here that 

 the greatest care and skill are required to insure the best possible 

 results. 



Capacity of floor space and trays. — In the case of kiln evaporators, 

 the sliced fruit is evenly spread on the floor to the depth of 4 to 6 

 inches. A kiln 20 feet square will hold the slices of 100 to 125 

 bushels of fresh fruit, depending upon the amount of waste in the 

 apples and the exact depth to which they are spread on the floor. 



If the fruit is in quarters or is dried whole it may be somewhat 

 thicker on the floor, since in these forms it does not pack down so 

 closely as the slices do and hence does not impede the circulation of 

 hot air through it if the depth is somewhat increased. 



In other types of evaporators where the fruit is handled on trays 

 the slices are seldom placed much more than 1 inch in depth. A tray 

 3 by 4 feet in size will hold about 25 pounds of slices, equivalent to 

 three-fourths of a bushel of whole fruit. 



The fruit is generally put on the floor of the kiln as fast as it is 

 sliced, and the fire is started in the furnace below as soon as the 

 floor is filled or. in many cases, before it is entirely covered. 



Oiling the floor* and trays. — It is a common practice to treat the 

 floor of kilns occasionally with tallow or a mixture of equal parts of 

 tallow and boiled linseed oil to prevent the fruit from sticking to it. 

 This is done several times during the season, as conditions appear 

 to make it advisable. Another practice with the same end in view is 

 to scrub the floors thoroughly twice a week with water, using with 

 it some one of the scouring soaps. This is preferred by some oper- 

 ators, who claim that oil or tallow discolors the fruit. 



At each filling of the trays, where these are used, the surface of the 

 wire netting is lightly wiped over with a cloth moistened in lard. 

 This prevents the fruit from sticking to the netting and keeps it 

 clean. 



Temperature to he maintained. — There is no. general agreement 

 among operators as to the temperatures which give the best results 

 in drying apples, and wide variations in practice exist without giv- 

 ing rise to any apparent differences in the appearance and market 

 quality of the product. The prevailing method among operators of 

 the kiln evaporator is so to regulate the fires for five or six hours 

 after loading the kiln that a temperature of 150° to 160 c F. will 

 be registered by a thermometer placed in a cleared spot on the kiln 



