32 STUDIES OF AMERICAN BARLEYS AND MALTS. 



For the determination of the extract in barley the following method 

 was used by Wahl: 



T \venty-five grains of finely ground barley were macerated with 2O) cc 

 of distilled water at 65 C. and 25 cc of diastase solution added. The whole 

 was immediately placed in a boiling water bath and kept at that temperature 

 for one hour. The mash was then removed from the bath, boiled briskly for 

 five minutes over a direct flame, stirring continuously, cooled to 60 C., and 75 

 cc of the diastase solution added, the temperature being kept at 60 to 75 C. 

 for thirty minutes, then raised to 70 C., and held there for another thirty min- 

 utes. After inversion, the mash was cooled to from 10 to 15 C., the weight 

 made up to 350 grams with water, and then filtered. The specific gravity of the 

 filtrate was determined by means of the pycnoineter. One hundred cubic 

 centimeters of diastase solution were then treated in the same way as was the 

 barley mash, and after cooling were made up to 100 cc, and the specific gravity 

 determined as before. The percentage of extract is calculated as follows : 



100 y _ (e-ed) 100 _ 



100-B N ' 



in which 



W = weight of water used in the mash. 



M= percentage of water in the barley. 



N= weight of barley used. 

 wd= weight of water in the diastase solution used. 



B= percentage of extract in mash filtrate according to Balling. 



e = extract in 25 grams of barley and 100 cc of diastase solution. 



E= percentage of extract in barley. 



ed=extract in diastase solution used. 



The diastase solution was made by digesting 500 grams of finely ground malt 

 with 2 liters of water for one hour at 15 C. 



Wahl's method for the determination of the extract yield a of the 

 malt was as follows: 



Fifty grams of the malt plus 3 kernels are finely ground into the mashing 

 beaker and are macerated with 250 cc of water at 45 C., immediately raised to 

 45 C., and kept at this temperature for thirty minutes. The temperature is then 

 raised 5 each five minutes until the thermometer shows 70 C. The mash is held 

 at this temperature for thirty minutes. The iodin test is made when the mash 

 reaches 70 C., and is repeated every five minutes until inversion has taken place. 

 The mash is then cooled to about 15 C., and its net weight is made up to 450 

 grams by the addition of water. The mash is thoroughly mixed, and a quan- 

 tity of clear wort, sufficient for the saccharometer determination, is filtered 

 through a coarse filter. The liquid is brought to a temperature of 15 C. Its 

 saccharometrical indication is determined by a special Balling instrument 

 standardized at 15 C. and divided into 0.05 per cent. The yield is calculated 

 by the following formula, in which " S " is the saccharometer indication, " II " 

 the percentage of water in the malt (both expressed in percentage of the malt), 

 and " E " the yield of extract : 



,_SX(800+H) 

 100 S 



"Report of the Analysis Committee, U. S. Brewers' Association, 1902. 



