CHAPTER V 

 THE ANALYSIS OF BUTTER 



Estimation of Water. Weigh a small round basin 

 (Fig. 33) about 3 in. in diameter, containing a small 

 rod ; place 5 to 10 grammes of butter therein, and 

 weigh again ; heat the basin over a very small flame, 

 or on a sand-bath, and stir constantly till frothing 

 has ceased, cool, and weigh again. The loss of weight 

 indicates water, and this multiplied by 100 and divided 

 by the weight of butter taken gives the percentage. 

 The flame should be of such a size that the butter takes 

 at least a minute to become melted. 



As an alternative method, about 2\ grammes of 

 butter may be weighed in a flat-bottomed basin, just 

 melted in the water-oven, and i| c.c. strong alcohol 

 mixed with the melted fat ; the basin is placed in the 

 water-oven for two hours, cooled, and weighed. The 

 loss of weight gives the water. 



Estimation of Curd and Salt. Wash the fat 

 from the basin after driving off the water by nearly 

 filling it with ether or amyl alcohol, and carefully 

 decanting the liquid after the solid portion has settled, 

 and repeating this four times ; if amyl alcohol is used, 

 it should be hot ; the residue is dried in the water-oven 

 for two hours and weighed after cooling. This repre- 

 sents curd and salt (if present). 



Extract the salt from the curd with hot water, and 

 filter the solution ; wash the residue and the filter, and 

 cool the filtrate ; add a few drops of potassium ch re mate 



solution, and titrate with silver nitrate solution till a 



faint red colour just appears ; each cubic centimetre 

 used is equal to 0,00585 gramme salt. 



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