APPENDIX B. 393 



ing a while, poured into or filtered into a weighe,d capsule. After evaporating the 

 alcohol and ether, the residue is heated in a drying oven at 100 to 105 C. to a constant 

 loss of weight. In beers rich in extract the ash contained in the glycerine can be 

 weighed and subtracted. In case the glycerine contains sugar, this can be determined 

 by Soxhlet's method and subtracted. 



XV. Hop substitutes are to be determined by Dragendorff 's method. Picric acid is 

 to be determined by Fleck's method. In examining for alkaloids, check experiments 

 with pure beer must in all cases be made. 



XVI. Sulphites. One hundred cubic centimeters of beer are distilled after the addi- 

 tion of phosphoric acid and the distillate conducted into iodine solution. After one- 

 third has distilled over, the iodine-colored distillate is acidified with hydrochloric acid 

 and baric chloride added. If sulphites were not contained in the beer no- precipitate 

 is observed, but at the utmost a turbidity. 



XVII. Salicylic acid. This may be shown qualitatively by shaking with ether, 

 chloroform, or benzine. The solution is allowed to evaporate, the residue dissolved in 

 water, and a very dilute solution of ferric chloride added. The addition of too much 

 acid and too violent shaking is to be avoided. The smallest trace of salicylic acid 

 may also be shown by dialysis, as it passes very readily through membrane. 



NOTE. All the results of an investigation are to be stated in percentages by weight. 



B. METHODS OF JUDGING PURITY OF BEERS. 



I. It is unjust to demand in a fermented beer an exact ratio of alcohol to extract, 

 as the brewer cannot regulate the degree of fermentation within narrow limits. As 

 a rule, Bavarian draft and lager beers contain from 1.5 to 2 parts of extract for each 

 part of alcohol, but a smaller proportion of extract would not necessarily prove the 

 addition of alcohol or glucose (the former to the beer, the latter to the wort). 



II. The degree of fermentation of a beer must be such that at least 48 per cent, of 

 the original extract has undergone fermentation. 



III. If glucose or other bodies poor in nitrogen have been used in appreciable 

 quantity as substitutes for malt, the nitrogen contents of the beer extract will fall 

 below 0.65 per cent. 



IV. The acidity of a beer should not be greater than 3cc. normal alkali to lOOcc. beer. 

 Acidity of less than 1.2cc. normal alkali to lOOcc. beer indicates previous neutraliza- 

 tion. If the acids are composed principally of lactic acid a larger quantity may be 

 present. 



V. The ash of normal beer is not above 0.3 grams to 100 grains beer. 



VI. The amounts of phosphoric and sulphuric acids and chlorine in beer extract 

 vary within such wide limits that their determination signifies nothing as to the 

 purity of the beer. 



VII. The amount of glycerine in pure beer is not greater than 0.25 gram to 100 

 grams beer. 



VIII. The following methods of clarifying beer are legal: (a) Filtration. (6) 

 Well-boiled hazel or beech shavings, (c) Isinglass. 



IX. The following methods of preserving beer are legal : (a) Carbonic acid, (b) 

 Pasteurizing, (c) Salicylic acid, this only for beers intended for export to countries 

 where the use cf salicylic acid is not forbidden by law. 



NOTE. The preceding methods are also to be used in the examination of imported 

 beer. 



C. ADMINISTRATIVE NOTE. 



It is absolutely necessary that the beer be preserved in well-corked green-glass bot- 

 tles. Stone jugs and such vessels are not to be used. 



The beer samples are to be protected from light and kept at a low temperature. 

 Care in making tests is, above all, necessary. 



