EVAPORATION OF APPLES 
40 pounds of water per bushel, or ap- 
proximately 5 gallons, passes off in the 
form of vapor. The evaporating of ap- 
ples may be said, in brief, to consist of 
driving off as rapidly as possible, by 
means of artificial heat, enough of their 
moisture to prevent deterioration through 
decay or other natural processes which 
occur in fresh fruit and at the same 
time to maintain a desirable texture and 
flavor. 
Buildings formerly used for other pur- 
poses are frequently converted into 
evaporators. An old dwelling house, a 
blacksmith shop, a cheese factory, and 
even a school house and a church are 
examples. Others are built substantially 
of brick or stone, thus reducing the risk 
from fire, which is an important consid- 
eration. 
A large quantity of fruit, in the ag- 
gregate, is still dried by primitive meth- 
ods. In rural communities, especially 
where the “home orchard” represents 
the extent of fruit growing, one often 
sees during the autumn a flat-topped 
rock, the roof of some low, easily acces- 
sible shed, or other flat surface on which 
have been spread apples, sliced or quar- 
tered, for drying in the sun. In some 
sections “strings” of quartered apples 
hanging by a doorway to dry, or behind 
a kitchen stove, are still familiar sights. 
While much of this sun-dried fruit is 
intended for home use, large quantities 
of it are marketed, and it is also export- 
ed to some extent. This fruit is common- 
ly referred to as “dried apples,” in dis- 
tinction from that handled in evapor- 
ators, which is known as “evaporated ap- 
ples.” 
Types of Evaporators 
Many types of evaporators are now in 
use, though in a general classification 
they may be grouped, for convenience, 
under a few heads. The more important 
of these are: 
Cook stove evaporators. 
Portable outdoor evaporators. 
Kiln evaporators. 
Tower evaporators. 
Miscellaneous types. 
It is well to emphasize, at this point, 
Ae WN 
919 
the fact that the descriptions which fol- 
low are representative of types only and 
that the details of construction and ar- 
rangement admit of endless modification. 
For the most satisfactory results, how- 
ever, In all types, thorough ventilation 
is essential to insure a good circulation 
of heated currents of air. 
Cook-Stove Evaporators 
Some of the cook-stove evaporators 
are small box-like structures, usually 
made of sheet iron or galvanized iron, of 
such a size that they can be placed on 
top of an ordinary cook stove. They are 
arranged for holding a series of small 
trays, on which the fruit is placed after 
it has been prepared for drying. Vari- 
ous sizes are in use, from one covering 
only a portion of the top of a common 
kitchen stove and having a capacity of 
only a bushel or so a day, to those re- 
quiring the entire top of a stove on which 
to operate it. 
Another style consists of a watertight 
rectangular box of tin, upon the upper 
surface of which the fruit is spread. The 
heat is supplied by boiling water, with 
which the evaporator is filled, the tem- 
perature being maintained by placing one 
end of the evaporator on top of a stove. 
There are various other styles of this 
type. 
Portable Outdoor Evaporators 
Portable evaporators are especially con- 
venient when it is desired to dry only a 
few bushels of fruit at any one time. The 
usual sizes have a capacity of 5 to 10 
bushels a day, and even more in some 
cases, although the quantity will of 
course vary with the attention given to 
them. As they are complete in them- 
selves and are not too heavy to be read- 
ily moved, they may be placed where- 
ever convenience from time to time dic- 
tates. 
There are other styles of this type ob- 
tainable from manufacturers which are 
made of sheet iron, usually galvanized. 
As no wood enters into their construc- 
tion, danger from fire is eliminated. One 
of these styles is provided with a heat 
deflector and so constructed that hot 
currents of air pass over the fruit as 
