20 BULLETIN' lilil, U. S. DEPARTMENT OF AGRICULTURE, 



Table 2. — The effect of washing curd on the strength of the casein. 



Buttermilk. 



Butter- 

 milk fut 

 content. 



Times 

 curd 



v. ashed. 



Acidity 

 of drain 

 water. 



Drying 

 temper- 

 ature. 



i B ''in 



required. 



Ash. 



Fat. 



HiO. 



Lot No. 



Portion 

 Mo ; 



Acidity. 



56.9 

 56.9 

 56. 10 

 56.10 



V, Jll . 

 .VI. 20 

 56.31 

 56.31 

 :,•;. :;:. 

 56.35 

 56.50 

 56.50 

 56. 52 

 56. 52 

 55. 52 

 56. 52 

 56.54 

 56. 54 

 56.56 

 56.56 



9A 

 9B 



10A 

 10B 



20A 



20B 



31 A 



31B 



35A 



35 B 



50A 



50B 



52 A 



52 B 



52C 



52 D 



51AC 



54BD 



56A 



56B 



P( r ci nt. 

 0.82 

 .82 



.72 

 .72 

 .81 

 .SI 

 .81 

 .81 

 .65 

 .65 

 .67 

 .67 

 .74 

 .76 

 .97 

 .96 

 .63 

 .63 

 .93 

 .93 



Per cent. 

 0.20 

 .20 

 .16 

 .16 

 .01 

 .01 

 . 12 

 .12 

 .19 

 .19 

 .06 

 .06 

 .32 

 .32 

 .32 

 .32 

 .07 

 .07 

 . 11 

 .14 





 4 

 2 

 4 

 

 4 

 

 4 

 

 5 

 

 2 

 

 4 

 

 4 

 4 

 

 

 4 



P( r ci nl. 

 0.60 

 .04 

 .19 

 .05 

 .54 

 . 14 

 .58 

 .05 

 .44 . 

 .07 

 .42 

 . 14 

 .42 

 .04 

 .57 

 .02 

 ■ 04 

 .37 

 .56 

 .02 



"F. 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 

 125 



Grams. 

 12 

 10 



9 



9 



9 



9 



9 



8 



9 



9 



8 



8 



9 



8 + 

 10 



9 

 9 



9 + 

 10 



8 + 



Per cent. 



1.65 

 0.26 



I. 18 



II. ss 

 2.18 

 1.26 



Per cent. 

 23. 32 

 22. 55 

 5. 86 

 6.04 

 4.29 

 4.07 



I'i f C( ill. 



6. B 1 

 5. 33 

 7.14 



7. 65 

 5. 91 

 5.08 









2. 38 

 0.86 



4.18 



I. 66 



5. 90 

 0.11 























































Table 2 gives data on the effect of washing the curd upon the 

 strength of the casein. The increased strength consistently shown 

 in the washed curd from high-acid buttermilk emphasizes the im- 

 portance of washing the curd from that kind of material. No notice- 

 able increase in strength could be found, however, in the washed curd 

 of low-acid buttermilk. Any difference in strength appears more 

 marked in the samples made from buttermilk of higher acidity or 

 fat content, substantiating the assumption that it was caused by a 

 combination of factors which by themselves may not have any direct 

 effect. The samples from the unwashed " curd, taken as a whole, 

 required more time to effect a complete solution, which may have 

 been caused by the free acid remaining in the whey rather than- by 

 any injury to the quality of the casein. A portion of the alkali is 

 used up in neutralizing the free acid found in the unwashed-curd 

 casein, thus leaving a weaker solution for dissolving the sample. 

 The reaction accounts for the decreased quantity of alkali found 

 necessary to dissolve the casein from a well-washed curd. 



DHYINC TKMl'KUATrr.F, OF THE CTTRD. 



A high drying temperature in combination with one of the other 

 factors has an injurious effect upon the quality of the casein which 

 is most pronounced with a high-fat or unwashed curd. A well- 

 washed curd from buttermilk of a low-fat content can be dried at a 

 relatively high temperature with no apparent injury to the quality, 

 but it is not to b'e recommended. The lower the temperature .the less 

 probability of injuring the quality, and for that reason the lowest 

 temperature possible should be used. A temperature of 130° F. 



