ORGANIZATION OF THE COOPERATIVE WORK, 1906. 



At the meeting of the Association of Official Agricultural Chemists 

 in 1904, tentative methods for beer analysis were reported and pub- 

 lished in the Proceedings for that year. "Since then similar analytical 

 methods have been submitted to all of the brewing schools of the 

 country and to the committee of scientists of the United States Brewers' 

 Association. The correspondence which followed developed many 

 interesting and valuable points and brought out several new analytical 

 methods that seemed worthy of study. Jn May, 1906, there was sent 

 to eight members of the association and five brewing institutes and 

 laboratories, who had signified their willingness to cooperate in beer 

 work, the following letter, accompanying samples as described and 

 giving methods for analysis to be used in the investigations: 



DEAR SIR: In response to your offer to dp cooperative work on beer analysis, I am 

 inclosing herewith directions for the examination of samples of beer which are being 

 shipped you by express. The methods as suggested explain themselves, I believe. 



My desire is to obtain full reports on the two samples for the purpose of comparing 

 results obtained by the different methods, omitting, if you wish, the glycerol and car- 

 bon dioxid results. The samples are numbered 1 and 2. One of the samples is pre- 

 served with sodium sulphite and the other with sodium fluorid. The beers have been 

 pasteurized and will keep for some weeks in a normal condition if in a cool place. 



I shall be glad to receive your reports on the samples, together with such com- 

 ments as you may make on the various methods as to their accuracy, practicability, 

 etc., at an early date. 



Thanking you for your willingness to aid me in this work, I am, 



Very truly yours, H. E. BARNARD, 



Associate Referee on Beer. 



PROVISIONAL METHODS FOR BEER ANALYSIS. 



[Submitted to collaborators for trial, 1906.] 



At present there is a decided lack of uniformity in the methods em- 

 ployed in the analysis of fermented beverages. Food chemists rely 

 for the most part on the provisional methods published in Bulletin No. 

 65 of the Bureau of Chemistry, Department of Agriculture. Chem- 

 ists in the brewing industry use certain other methods, and there is a 

 lack of agreement as to the most suitable and accurate method of 

 analysis. In order to decide upon standard methods as fairly and 

 accurately as possible it will be necessary to give each of the many 

 different methods employed for the determination of the various factors 

 a thorough trial. It is therefore, recommended that in making analyses 

 of the samples the directions be followed as closely as possible and 

 results expressed in the form indicated. 



PREPARATION OF SAMPLE. 



Bottled beers are always under pressure because of the carbon dioxid present, 

 either as the result of natural fermentation or artificial carbonating. To remove 

 all undissolved carbon dioxid (A) pour contents of bottle into a large flask and shake 

 vigorously to hasten the escape of gas ; (B) drive off gas by pouring sample from one 

 tall beaker to another until on standing no gas bubbles are seen to rise. In pre- 

 paring the sample see that the temperature is not lower than 15 C. 



Object: To determine, first, whether method (A) secures as complete a separation 

 of carbon dio'xid as (B) and, second, to see if any loss of alcohol is observed when 

 samples are exposed to open air, as in method (B). 



Provisional methods for the analysis of foods, p. 92. 



[Cir. 33] 



(3) 



