43 The Sweet Potato 



verting into sugars, the sweet potato also contains an 

 average of about 4 per cent actual sugar, making an 

 average of about 22 per cent of alcohol-producing ma- 

 terial. Keitt found that a bushel of sweet potatoes 

 would produce on an average a little more than a gallon 

 of commercial alcohol. As varieties differ materially 

 in starch and sugar-content, the amount of alcohol pro- 

 duced by a given quantity of sweet potatoes would 

 naturally be influenced by varietal kind. With the in- 

 creased demand for denatured alcohol in art and science, 

 it is probable that this crop will furnish an important 

 source of raw material for manufacture. 



Sirup from sweet potatoes. 



Experiments conducted in the Bureau of Chemistry, 

 United States Department of Agriculture, have pro- 

 duced a palatable and wholesome sirup from sweet po- 

 tatoes. The method is recommended particularly for 

 home use when there is an over-supply of sweet po- 

 tatoes that cannot be marketed to advantage. It is not 

 advocated at present for commercial use, because it is 

 believed that sweet-potato sirup cannot compete on a 

 commercial basis with grain sirups. The process of 

 manufacture is described as follows : ^ 



" The sweet potatoes should be washed, any decayed 

 portions or other blemishes removed, and then weighed. 

 They are then placed in a kettle with plenty of water 

 and boiled until thoroughly soft. Erom 1% to 2 hours' 

 boiling is required. The potatoes are then mashed in 

 the kettle in the water in which boiled, with sufficient 

 water, adding more if necessary to form a thick, smooth, 

 mushy liquid. The temperature of the mixture is then 

 1 " Weekly News Lefter," U. S. Dept. Agr., Feb. 12, 1919, p. 6. 



