80 BULLETIN 274, U. S. DEPARTMENT OF AGRICULTURE. 
It is not uncommon where salt has been added at each re-icing en 
route to find spoilage both from freezing and from deterioration on 
account of too high temperatures. In such cases the temperature at 
the floor next to the iced bunkers becomes sufficiently low to cause the 
treezing of some of the fruit on the floor in the ends of the car, while 
at the top in the middle of the car the temperature is often so high 
that the fruit is in an overripe condition. The temperature tests made 
in fully loaded cars of berries in transit would indicate that it is not 
os ordinarily advisable 
=! to add salt in re 
icing after the first 
40 hours in transit. 
During the first part 
of the journey and 
before shipment no 
doubt the addition of 
a certain percentage 
of salt to the crushed 
ice in the bunker 
greatly aids in ob- 
taining quick cooling, 
but the addition of 
salt at each re-icing 
during a journey of 
over 40 hours may 
| (i 
35 a 
AUGUST // 
AUGUST /2 GUGUST 
| 
4UGUST 
Iric. 26—Diagram illustrating the average temperature of 
fruit in top and bottom tiers and average temperature 
of all fruit in the car of blackberries in transit from 
Povalluy, Wash,, to Grand Forks, N. Dak., season of 
oO. 
result in consider- 
able damage by freez- 
ing in certain por- 
tions of the car. If 
there was some way of circulating the cold air throughout the 
car so as to prevent the formation of cold pockets. salting through- 
out at every re-icing would doubtless be highly beneficial. Possibly 
the use of slats or racks on the floor would facilitate the free cir- 
culation of cold air sufficiently to avoid the danger of freezing, even 
though salting was practiced throughout en route. 
THE APPLICATION OF PRECOOLING. 
As a result of these investigations, every effort has been made by 
the industry to procure proper handling, and a precooling plant has 
been erected for cooling the fruit after loading it into the cars. 
After observing the methods of operating a number of precooling 
plants, one is impressed with the need of organizing or adjusting the 
fruit picking and delivery so as to allow sufficient time to precool 
the fruit successfully before it enters upon its journey to a distant 
market. The most serious and common fault is that of allowing too 
little time for precooling; that is, attempting to do precooling in 
less than half or quarter of the time actually necessary to accomplish 
the desired results. Our experience has demonstrated beyond ques- 
tion that the effective precooling of berries can not successfully be 
accomplished in less than four or five hours. The precooling of a 
car, fully loaded, for an hour or two hours accomplishes little in 
the way of actual temperature reduction or in results from the stand- 
point of the condition of the fruit on arrival. The investigations of 
* — >) o 
