ALCOHOL 



25 



certain substances called enzynis, which 

 usually are developed for this particular 

 purpose in a portion of the grain used 

 for mashing, by a process called malting. 



Malting — When the seeds of any cereal 

 are moistened and allowed to sprout, 

 changes in their chemical composition 

 take place which are fully as striking as 

 the accompanying changes in the appear- 

 ance of the grains. Most important of 

 these is the formation of bodies which 

 have the power, when dissolved in water 

 and allowed to act at a suitable degree of 

 warmth, of corroding the insoluble starch 

 granules of the grain, of rendering them 

 soluble, and of converting the starch ulti- 

 mately into a fermentable sugar called 

 maltose. Grain which has been treated 

 so as to develop these bodies is called 

 malt. 



These enzyms, or active bodies of the 

 malt, are usually grouped under the name 

 diastase, and they appear during the 

 sprouting of all starchy seeds. Their for- 

 mation has been utilized technically in 

 the case of several of the cereals, such 

 as wheat, rye, oats, maize, and barley. 

 Rye and barley produce diastase more 

 abundantly than the other grains, and are 

 employed in large quantities in the malt- 

 ing industry. Of the two, barley is most 

 used on account of the protection which 

 is afforded by its husk to the tender ker- 

 nel of the grain during the rough handling 

 incidental to the malting process. 



In making malt the barley is cleaned 

 thoroughly by screening and washing, and 

 is then steeped in water until the grains 

 have absorbed enough water to soften 

 them thoroughly and prepare them for 

 germination. The excess of water is then 

 drained off, and the wet grain is spread 

 evenly on a smooth and scrupulously clean 

 floor in a well-ventilated room which can 

 be kept at a temperature of about 55 de- 

 grees to 60 degrees Fahrenheit. The grain 

 is turned frequently, with wooden shovels, 

 to keep it uniformly moist and to prevent 

 its overheating, and as sprouting pro- 

 gresses it is gradually spread over a great- 

 er floor area so that a pile which originally 

 was from 12 to 18 inches deep may finally 

 have a depth of only three or four inches. 



Malt which is intended for shipment is 

 usually grown for about a week at a tem- 

 perature not exceeding 6S degrees Fahren- 

 heit, after which it is dried slowly in 

 kilns that are gradually raised from 95 

 degrees to 125 degrees, until only two or 

 three per cent of moisture remains. Malt 

 which is made in the distillery where it 

 is to be used may be grown at about 55 

 degrees for three or four weeks, and 

 should then be used without having been 

 dried. Green malt, thus prepared, has a 

 much higher diastatic power (1) than the 

 dried malt of commerce. 



One hundred pounds of good barley will 

 make about 75 pounds of kiln-dried dis- 

 tiller's malt, which will be strong enough 

 to saccharify about 1,000 pounds of raw 

 grain (maize). The same barley, grown 

 longer and used as green malt, can be 

 made to saccharify nearly twice as much 

 raw grain. 



In converting starch into sugar, malt 

 diastase exerts two distinct forms of chem- 

 ical activity — liquefaction, and sacchari- 

 fication. The intensities of these activ- 

 ities depend largely upon the temperature 

 at which the diastase is made to act upon 

 the starch, and the two forms of activity 

 are differently affected by alterations in 

 this temperature. The liquefying power is 

 exerted most strongly at about 158 de- 

 grees Fahrenheit, is weakened at approxi- 

 mately 175 degrees, and is destroyed at 

 about 200 degrees. The saccharifying 

 power is strongest between 120 degrees 

 and 130 degrees Fahrenheit, is weakened 

 seriously at 145 degrees, and is destroyed 

 completely at 175 degrees. These facts 

 show the need of drying distiller's malt 

 at a relatively low temperature, and indi- 

 cate the temperature limit below which 

 saccharification must be conducted. 



Mashing — The first stage of every mash- 

 ing is a scalding, which gelatinizes and 

 partially liquefies the starch of the raw 

 materials. When this preliminary cook- 

 ing has gone far enough, the mash is 

 cooled somewhat and malt is added, where- 

 upon the liquefaction is completed and 

 the soluble starch is more or less com- 



(1) The power of converting starch into 

 sugar. 



