2 CIRCULAR 7 4 0, IT. S. DEPARTMENT OF AGRICULTURE 



USE OF COLD STORAGE FOR FRUIT 



Holding apples and pears in cold storage in producing areas rather 

 than at market terminals or at points in transit has become a com- 

 mon practice in recent years. In the Pacific Northwest this change 

 has been more or less coincident with the decline of speculative buy- 

 ing of the fruit by eastern interests and with the growth of cooper- 

 ative marketing enterprises owned and controlled by the growers. 

 As a result the available cold-storage space in the fruit-growing dis- 

 tricts in Washington and Oregon has been materially increased, 

 but even yet it is inadequate for the needs of the industry. Many of 

 the existing cold-storage plants are inadequately equipped to handle 

 satisfactorily the tonnage stored. Year by year there is remodeling 

 and expansion of existing plants, as well as new construction to provide 

 additional refrigerated storage space. Some of the storages are well 

 designed and carefully and efficiently operated ; others are not. It is 

 the purpose of this circular to present in concise language, as non- 

 technically as possible, the essential features in the design and oper- 

 ation of cold-storage plants and in the handling of the stored fruit 

 in the Pacific Northwest, although the same principles will be found 

 equally useful in other parts of the country. 



The principal fruits requiring refrigeration for storage are apples 

 and pears. Grapes also are stored extensively in some places, par- 

 ticularly in California. Refrigeration is used also for the precool- 

 ing or short-time storage of other fruits. 



As rural electrification and automatic refrigeration equipment 

 have become more available, individual fruit growers or small groups 

 of growers have been building cold-storage plants at or near their 

 orchards instead of relying on large plants that serve a whole com- 

 munity or a large number of growers. This has been coincident 

 with the development of better handling and packing methods. The 

 time, labor, and facilities required for sorting and packing have 

 demanded refrigeration near the orchard, so that packing and ship- 

 ping will not be under the pressure of getting the job done in a matter 

 of a few days after picking. Having refrigeration facilities at hand 

 has permitted the orchardist to give his fruit optimum protection 

 while it is awaiting packing and to employ a comparatively small 

 crew of skilled sorters and packers instead of having to mobilize large 

 crews, oftentimes of persons who know little or nothing about fruit 

 handling or packing. This has been especially important under war 

 conditions, when the utilization of efficient cold-storage facilities near 

 the orchards has been imperative to take the fullest advantage of a 

 short labor supply as well as to prevent wastage of fruit that is a 

 vital part of the Nation's food supply. 



Many of the cold-storage plants designed and operated along lines 

 found satisfactory for general cold storage have been neither efficient 

 nor economical for fruit, owing to specialized requirements for the 

 rapid cooling of the fruit and the maintenance of its temperature 

 within narrow limits. For best possible returns on investments, 

 emphasis must be placed upon both the design and the efficient oper- 

 ation of a fruit cold-storage plant. 



Many cold-storage operators, including foremen and plant engi- 

 neers, will desire more detailed information on many subjects that 



