ALCOHOL 



17 



fortunately, the fermentable substances 

 — sugar, starch, etc.^ — are often not deter- 

 mined individually, but are combined 

 and reported as "nitrogen-free extract," the 

 percentage of which is obtained by sub- 

 tracting the sum of the other components 

 from 100. The value thus obtained for 

 "extract" will of course include not only 

 the sugar and starch, but also the un- 

 fermentable pentosans and the sum of 

 the errors made in determining the per- 

 centages of the first five components. For 

 these reasons the fermentable material 

 actually present may be lower than the 

 figures for nitrogen-free extract or car- 

 bohydrates would indicate, as from 5 to 

 10 per cent of this extract may be un- 

 fermentable. Whenever possible, repre- 

 sentative analyses have been used show- 

 ing the amount of starch, sugar, and un- 

 fermentable pentosans as individually de- 

 termined and not as found by subtrac- 

 tion. 



Saccharine Materials 



Agave — Different species of this plant 

 are used in the Southwest in the prep- 

 aration of several varieties of distilled 

 alcoholic liquors, and at least one dis- 

 tillery has been erected in the hope of 

 utilizing them as a source of industrial 

 alcohol. It is known that the juice of 

 these plants contains large amounts of 

 sugar at times, and there is every rea- 

 son to believe that, with proper technical 

 direction, they can be used profitabl.v for 

 indu-strial purposes.* 



Fruits — The average amount of sugar 



contained in some of the common fruits 



is shown in the following tabulation: 



Average por- 



centaee of 



total sugars. 



oalcnlatpd as 



dextrose. 



Apple 12.2 



Banana 13.8 



Grape 15.0 



Orange 5.4 



Peach 7.6 



Pear 10.0 



Pineapple 11.7 



Prickly pear 4.2 



Tomato 2.0 



Watermelon 2.5 



• A sample of one of these plants, sotol 

 iDasj/Urion tcxaiium t . was analyzed in the Bu- 

 reau of Chemistry and found to yield 16 per 

 cent of levulose. 



It must not be supposed, however, that 

 it is practicable to obtain all of the su- 

 gar in these fruits in a form suitable for 

 fermentation. It would be necessary, in 

 preparing any of them for distillation in 

 a column still, to express the juice from 

 the marc, since the latter, if allowed to 

 enter the still would impede its working, 

 and obviously a certain proportion of 

 the juice and of the sugar will remain in 

 the marc. 



Thus it is estimated that it would be 

 impossible, in working with apples, to ob- 

 tain more than 75 per cent of the total 

 fermentable material, or about 9 per cent 

 of the the weight of apples delivered. On 

 this basis, a ton of average apples should 

 yield about 14 gallons of alcohol. Esti- 

 mating the cost of gathering culls and 

 windfalls, and of delivering them at the 

 mill, to be $4 per ton, a figure based on 

 actual experience, the raw-material ex- 

 pense for a gallon of alcohol will be at 

 least 28 cents. 



In the case of grapes, assuming that 

 approximately 80 pounds of juice may be 

 expressed from 100 pounds of Concords, 

 and that this juice contains 18 per cent 

 of total sugars, a ton of fruit should yield 

 between 21 and 22 gallons of alcohol. If 

 the expense of picking and hauling grapes 

 to the distillery is placed at $6 or $7 a 

 ton, a figure obtained from a grape-grow- 

 ing district in California — the cost of raw 

 material for a gallon of alcohol will be 

 30 cents. 



In the case of watermelon, if a 90 per 

 cent extraction of juice containing 2.5 

 per cent of sugars is obtained, a ton of 

 melons will yield about three and one- 

 half gallons of alcohol. If the cost of 

 gathering and hauling the fruit is set at 

 $2 per ton, the raw-material cost will 

 be not less than 50 cents per gallon of 

 alcohol. 



In these three specific cases, it has 

 been assumed that the fruit itself was 

 valueless on the spot where grown, and 

 that it could be delivered at the distillery 

 for the mere cost of gathering and haul- 

 ing. Even on that basis, it would be 

 too costly to use as raw material in mak- 

 ing industrial alcohol. The fact that fruit 



