SOURCES OF STARCH 



167 



because small granules can penetrate further than large ones 

 and be more thoroughly absorbed by the fabric. Rice, because 

 of the minuteness of its granules, yields the best laundry starch, 

 but this is expensive and is used only for the finest materials. 

 Corn is abundant in the United States and its starch granules 

 are small ; the laundry starch made from corn is very good and 

 is very widely used in this country. Potato starch, because of 

 the ease and cheapness with which it can be manufactured, is 

 also widely used, though inferior to the starch made from rice 



or corn. 



Potato starch is made by shredding or rasping potatoes in 

 water and then straining the entire mass through a fine sieve. 



FIG. 61. Magnified starch granules : 



Only the minute starch granules and the water escape through 

 the small openings of the sieve. The escaping starch and water 

 run into vats and are left undisturbed there until the starch 

 settles to the bottom and the water can be drained off. The 

 caky starch mass is then dried and broken into lumps or ground 

 into powder. 



