Phipson.- —Transformation of Barley into Malt. 329 



being due to this substance. Cytase converts the cellulose into 

 sugar (dextrose), and this, passing through the scutellum, is 

 used by the germ as food.* The diastase acts upon the now 

 exposed starch and converts it into maltose, no dextrin being 

 formed. The maltose passes from where it is formed in the 

 endosperm to the germ, but, while transfusing, this scutellum 

 is apparently converted into cane-sugar in an unascertained 

 manner. This cane-sugar now formed is used by the germ as 

 food. A portion of it is inverted into invert sugar by an enzyme 

 called " invertase " that is secreted in the neighbourhood of the 

 rootlets. 



While these changes are taking place an analogous process 

 is also going on with the nitrogenous matter. The nitrogenous 

 constituents of malt consist principally of glutens. These are 

 acted upon by the peptase, and are converted into peptones, 

 amides, amido-acids, and albuminoids proper, the former passing 

 readily through the scutellum and forming the nitrogenous 

 portion of nutriment of the germ. 



From the above you will realise what an enormous amount 

 of energy is lying dormant within the germ of the barley-corn, 

 and only waiting the addition of water at a suitable temperature 

 to bring these numerous and complex changes about. 



On a commercial scale the process is carried out in the fol- 

 lowing manner : The barley, after having been thoroughly 

 cleaned by passing through screening machinery, and graded to 

 take out the light, thin corns, is then immersed in water in a 

 large tank known as the cistern. The barley is allowed to soak 

 for about fifty hours ; but, of course, this will vary very much 

 according to the nature of the barley and the temperature of 

 the steep-water, which should be from 50° to 55° Fahr. If 

 the water is below this temperature it tends to delay germina- 

 tion. 



While in the cistern the barley absorbs about 50 per cent. 

 of water, and its proportions increase considerably in bulk. 

 The lower the initial moisture of the barley the more rapidly 

 does it absorb water. This is a matter of importance, as barley 

 grown on undulating land — as much of the New Zealand barley 

 is — invariably shows great irregularity in the amount of initial 

 moisture ; consequently some of the grain absorbs more water 

 than the other while in the cistern, which, in turn, means 

 uneven growth. To remedy this, many maltsters now adopt 

 the system of sweating prior to steeping. By the term " sweat- 

 ing " is meant kiln-drying. The barley, before being stored in 

 bins, is subjected to a temperature of about 100° Fahr. on the 



* H. Brown and Morris. 



