VARIETIES OF BARLEY 323 



compounds are precipitated, causing a hazy appearance in the 

 beer which is not desired, particularly when bottled. It is now 

 claimed, however, that during the process of beer making these 

 insoluble proteids may be changed into soluble proteids if proper 

 conditions are offered, by a peptonizing enzyme which occurs 

 naturally during the process of malting barley. The conditions 

 which favor the development of the enzyme are time and tempera- 

 ture. The longer the growth of the malt and the lower the 

 initial mashing temperature, the more fully will the insoluble 

 proteids be made soluble and the more readily will the remaining 

 insoluble proteids be precipitated by cold storage. 



446. Germination. — The maximum, minimum and best tem- 

 perature of the germination of barley is practically identical with 

 that of wheat. Saunders tested the viability of two varieties of 

 barley during six years as follows: 97; 91; 79; ^6; 20; S} Todaro 

 found the germination of barley to decrease in four years from 

 eighty-seven to fifty-eight per cent.^ The vitality of barley is 

 easily injured by heating in stack or bin. In practice, barley 

 that is more than t^vo years old is not considered safe for malting 

 purpose, but its germinating power increases for a few months 

 after threshing, especially if it has not been stacked. A distinc- 

 tion is made between germinative capacity and germinative 

 energy. The former is its capacity to germinate irrespective of 

 time, and should not be below ninety-five per cent ; while germina- 

 tive energy is the ability to germinate within a definite time, and 

 should not be below seventy per cent at the end of t^vo days or 

 ninety per cent at the end of three days at a temperature of 

 80° F. 



II. VARIETIES. 



447. Species. — There are two well-marked types of barley; 

 (i) six-rowed barley (^Hordciim sativum hcxastichon Hackel), 



1 Can. Expt. Farms Rpt. 1903, p. 44. 



« Staz. Sper. Agr. Ital. 31 (1898), No. 6, pp. 525-563. E. S. R. XI, 157. 



