WHEAT-GROWING AND ITS PROBLEMS 297 



of a new country, continuous wheat growing is displaced by 

 a more general system of agriculture that includes the cultivation 

 of grass and clover mixtures. 



The Quality and Composition of the Grain 



The different varieties of wheats show considerable differ- 

 ences in the flour they yield. The exacting requirements of 

 modern civilisation necessitate special sorts of wheat for special 

 purposes. The baker, the confectioner, the biscuit-maker, all 

 have their own requirements, and modern fastidiousness has put 

 a price on subtle differences that were not recognised fifty years 

 ago. Some very interesting problems have thus been opened 

 up which are, as yet, far from being solved. In particular many 

 investigations have been made to discover why certain flours — 

 the so-called weak flours — only give small, squat, heavy-looking 

 loaves, whilst others — the strong flours — will yield large, well- 

 shaped, well-aerated loaves. The strong wheat commands the 

 higher price, as the public insists on having the large loat ; 

 whether it is intrinsically more valuable, whether it is more 

 nutritive, has yet to be ascertained. 



A. E. Humphries has set out the various properties which 

 wheaten flour should possess in order to rank high in the miller's 

 estimation. There are at least five involved: (i) "stability," 

 the facility with which large masses of dough can be handled 

 in the bakehouse ; (2) the capacity for making a large quantity 

 of bread from a given weight of flour ; (3) the capacity for 

 making large, well-piled loaves ; (4) colour, it being desirable 

 that both crumb and crust should be bright in appearance and 

 not dingy ; (5) flavour. These have not yet been correlated 

 with the chemical composition of the flour, but a start has been 

 made. An excellent critical summary of the present position 

 of this problem was given by E. F. Armstrong at Winnipeg. 



Perhaps most work has been done on the capacity for 

 making large, shapely loaves which has usually been the 

 definition of " strength " in wheat. This depends on two 

 factors : (i) the gluten (the sticky, elastic part of the flour) 

 must be capable of holding the bubbles of gas which give the 

 necessary spongy texture ; (2) there must be sufficient gas 

 generated to distend the gluten to its utmost extent. The older 

 hypothesis was that strength was regulated by the amount of 

 gluten ; the more gluten, the greater the gas-holding capacity, 



