312 



FOOD AND FOOD ADULTERANTS. 



DETECTION. 



The detection of the addition of very small quantities of bicarbonate 

 of soda to beer is by no meaus an easy matter when the constant pres. 

 ence of soda salts in beer ash is considered, and the very variable con- 

 tent of alkali in the waters used for brewing purposes. The ash of beer 

 is of very variable composition, being obtained in part from each of the 

 principal constituents which enter into the preparation of the drink, 

 viz, the malt, the hops, and the water used in the brewing. The con- 

 tent of soda (Na 2 O) in the ash varies in different published analyses, 

 from less than 4 per cent, up to 35 per cent, of the ash, 1 and this without 

 a sufficient proportion of chlorine to account for the large per cent, of soda 

 as salt. The presence of any considerable quantities of carbonate in 

 beer ash, however, is abnormal, and indicates the addition of bicarbon- 

 ate of soda to the beer, the acetates, lactates, &c., formed from it being 

 converted into carbonates by the process of incineration. So far as I 

 have been able to ascertain, no carbonic acid has ever been found in 

 the ash of normal beer, its alkalinity being due to the presence of alka- 

 line phosphates. I have found no statement as to whether the ash of 

 normal beer reacts acid or alkaline in any of the books on the subject 

 except Eisner, 2 who says it reacts acid. This must certainly be a mis- 

 take, for the ash of every sample I examined gave a strong alkaline re- 

 action, requiring from 5 to 3.5cc. of decinormal acid for the neutraliza- 

 tion of the ash from lOOcc. of beer. HassalF says, on the other hand? 

 "the alkalinity of the ash must be estimated" in determining whether 

 some alkaline earth or alkali has been added. 



In order to investigate this question I procured a sample of beer made 

 in Lafayette, Ind., which was guaranteed to contain no bicarbonate of 

 soda, and which, from my knowledge of the parties through whom it was 

 obtained, I have every reason to believe to be a sample of perfectly 

 pure beer. 4 



The complete analysis of this sample was as follows : 



Several portions of lOOcc. each were taken, various quantities of bi- 

 carbonate of soda added, and after solution each portion evaporated 



1 See Wolff, Aschen-Aualysen, p. '23. 



* Page 89. 



3 Page 70G. 



H A small quantity of rico grit \v:is ailmittml to havo boon nsoil in its Manufacture. 



