THE DISTILLING INDUSTRY IN IRELAND. 501 



The ]\Ianufacture of Whiskey. 



It is impossible in the course of a short article to give a full account of 

 the processes involved in the manufacture of spirits, but a short description 

 of the main facts as to the " death, burial, and resurrection of John Barley- 

 corn " rnay prove not uninteresting. 



All substances containing either sugar or starch will yield spirits on being 

 fermented ; but in the case of grain and other starch- 

 The Production of containing substances, the starch has to be first con- 

 Alcohol. \erted into sugar. In France and many other 

 countries a large quantity of spirit is prepared from 

 beetroot, potatoes, and the fermented juice of the grape, and in Jamaica 

 and some other places, directly from sugar cane. In this country, however, 

 most alcohoHc spirits are obtained by the distillation of the fermented 

 extracts of grain. The process of miaking spirits from corn may be divided 

 into two stages, viz. : — first, the formation of the alcohol, and secondly, its 

 elimination from the unfermentable ingredients with which it is mixed ; in 

 other words, the whole process may be divided into the two stages of 

 brewing and distilling. The first step in the former process is to saccharify 

 the starch contained in the grain. The usual method to accomplish this is 

 to mix malted barley with the raw grain, as malt contains a substance 

 known as " diastase," which has the effect, when mashed with unmalted 

 grain at certain temperatures, of converting the starch of the grain materials 

 into a saccharine extract capable of fermentation. The process of malting 

 and the change produced in the malted grain have been explained in the 

 preceding article (see page 461). The next step in the process is the 

 actual brewing. The raw grain is crushed in a mill and then passed with 

 the malt into the mash-tun, where, as in making beer, the meal is submitted 

 to the action of water at a certain temperature, and by means of revolving 

 arms the " grist " is thoroughly incorporated with the water. The insoluble 

 starch in the grain is thus converted into the soluble saccharine fluid known 

 as " wort." As this saccharine fluid is required by distillers for its alcohol 

 only, all Irish distillers, w4th two exceptions, use a considerable quantity of 

 unmalted grain, and in some Patent Still establishments over So per cent, 

 of the mixture mashed consists of raw grain. 



The wort is run off from the mash-tun through the perforated false 



bottom into the underback, and the grains remaining in the mash-tun are 



re-mashed several times until they are practically exhausted of all their 



soluble constituents, after w^hich the grains are utilised for feeding 



cattle. The wort, after being cooled, is then passed into the fermenting 



vessels, and yeast being added, the process of fer- 



Fermentation. mentation begins. The chemical actions which take 



place have been already described in the article on 



brewing ; the main feature is the conversion of the fermentable sugar, by 



the influence of yeast, into alcohol and carbonic acid, and as the secondary 



products are of but small importance, the conversion may be represented by 



the following chemical equation : — - 



Ce H,, Oe = 2C, Kg O + 2C O., 

 (Glucose) (Alcohol) (Carbonic Acid) 



