98 



BULLETIN 433, U. S. DEPARTMENT OF AGRICULTURE. 



taken in 14 beef coolers in 6 modern meat-packing establishments. 

 The results of these observations are presented in Table 61 : 



Table 61. — Humidity of beef coolers in six meat-packing establishments. 



Cooler 

 No. 



System of refrigeration. i 



Condition of cooler. 



Per 



cent hu- 

 midity. 



Remarks. 



1 



Sheet brine 



Good 



87 



95 

 92 

 95 



100 



92 

 93 



92 

 93 



93 



93 



93 

 92 

 95 



Half filled with beef killed 3 



days previously. 

 Half filled with chilled beef. 

 Do 



2 





do 



3 



Sheet brine 



do 



4 



do 



do 



Cooler for ripening cuts of 

 meats for hotels, etc. Filled 

 with cuts of beef, many of 

 v\hich showed growths of 

 molds. 



Filled vdth dulled beef 



5 



... .do 



Air filled with water va- 

 pors coming from adjoin- 

 ing cooler being filled 

 with warm beef. 



Good 



6 



do 



Half filled with chilled beef 



7 

 8 



Direct expansion of am- 

 monia in overhead bun- 

 ker. 



do 



Fair. Walls and ceiling 

 damp. 



Fair 



Filled with chilled beef. 

 Do 



9 



Closed brine coils 



Fair. Some condensation 



of moisture on ceiling. 

 Fair 



One-third filled with chilled 



10 



do 



beef. 



11 



Brine spray 



Fair. Walls and ceiling 



damp. 

 Good 



ton, veal, and "edible offal." 



One-third filled with chilled 



12 



do 



beef. 

 Filled with chilled beef 



13 



..do 



do. 



Nearly filled vnth chilled beef. 



14 



Closed brine coil 



do. 











1 Overhead bunkers were used in each cooler. 



The data presented in Table 61 show that for the most part the 

 humidity of the beef coolers ranged from 92 to 95 per cent of satu- 

 ration. Data showing the humidity of fore coolers filled with warm 

 beef are not presented, since observations that have been made in 

 such coolers have shown the air to be saturated with water vapors. 



The effects of hmnidity upon the length of time that fresh beef can 

 be held in cold storage are shown very clearly by the results of the 

 cold-storage experiments carried on in the bureau's cold-storage 

 room as compared with the one conducted in the packing-house 

 cooler. The character of the beef was practically the same in the two 

 cases, and the temperature of the pacldng-house cooler was slightly 

 lower than that of the bureau's cold-storage room. The chief vari- 

 able factor was humidity. The humidity of the bureau's cooler 

 ranged from 70 to 85 per cent of saturation; that of the packing- 

 house cooler from 92 to 95 per cent. The much higher humidity of 

 the packing-house cooler was undoubtedly the reason why it was 

 impossible to hold beef in storage in that cooler for longer than 55 

 days, whereas beef was held in the bureau's cold-storage room, hav- 

 ing a slightl^^ higher temperature but a much lower humidity, for 

 as long as 177 days. 



These observations emphasize the importance of humidity as a 

 factor affecting the length of time that fresh beef can be held in cold 

 storage. 



In addition to the three important factors which have been dis- 

 cussed as affecting the storage period of fresh beef, various other 

 factors may under certain conditions exert their influence. 



Summari/. — In light of the various factors that affect the length 

 of time that fresh beef can be held safely in cold storage at tempera- 



