MASHING. 175 



about three quarters of an hour, the tun is then cov- 

 ered, and the whole is left quiet for about the same 

 time, or rather longer. 



416. Two objects are attained in the process of 

 mashing ; the soluble matters in the malt are ex- 

 tracted, and a further portion of the starch is con- 

 verted into sugar and gum, by the influence of the 

 diastase which the malt contains (685) ; and hence, if 

 a quantity of raw grain is mixed with the malt, the 

 starch which it contains will be found to be converted 

 into sugar and gum in the mash-tun. 



417. It is of the first importance to use water of a 

 proper temperature in the mash, tun ; a good deal of 

 heat is given out in the process of mashing, and this 

 must be allowed for. If the water is too hot it con- 

 verts the starch into a jelly, which interferes with its 

 conversion into sugar; this is called setting the mash. 

 If on the other hand the mash is too cool, the con- 

 version of the starch into sugar will likewise be very 

 slow and imperfect, and the wort will have a great 

 tendency to turn sour. 



418. When the mash is complete, and the wort has 

 become clear, it is run off from the spent grains ; 

 which are then mashed a second time with fresh warm 

 water, to dissolve the soluble matters still left in the 

 grains after the first mashing. The product of the 

 first mash alone is used for ale, while that of the sub- 

 sequent operations is employed for common or small 

 beer. Sometimes the grains are subjected even to a 

 third mashing. 



