UNITED STATES DEPARTMENT OF AGRICULTURE 
BULLETIN No. 330 
Contribution from the Bureau of Plant Industry, Wm. A. 
Taylor, Chief, and the Bureau of Chemistry, 
Carl L. Alsberg, Chief 
SZ& < &J'U 
Washington, D. C. 
January 8, 1916 
THE MILLING OF RICE AND ITS MECHANICAL 
AND CHEMICAL EFFECT UPON THE GRAIN. 
By P. B. Wise, Assistant, Office of Grain Standardization, and A. W. Bkoomell, 
Assistant Chemist, Food-Control Laboratory. 
CONTENTS. 
Page. 
Introduction 1 
Geographical distribution and value of 
the rice crop 1 
Structure of the rice grain 2 
Milling methods 4 
Evolution of rice milling 4 
Primitive methods 4 
Modern milling 7 
Effects of milling on rice 14 
Mechanical effect 14 
Chemical effect 18 
Milled rice and its by-products 22 
Mechanical analyses and mill yields 22 
Chemical analyses 26 
Summary 29 
INTRODUCTION. 
GEOGRAPHICAL DISTRIBUTION AND VALUE OF THE RICE CROP. 
From early colonial days until the Civil War, rice was an impor- 
tant crop in the coastal plains of South Carolina and the adjacent 
States. During the past quarter of a century, however, the produc- 
tion of rice in Louisiana, eastern Texas, and Arkansas has risen to a 
preeminent position. Of the 1913 rice crop of the United States, 
valued on the farm at $22,090,000, approximately 45 per cent was 
grown in Louisiana, 38 per cent in Texas, and 15 per cent in Ar- 
kansas. The relative importance of the rice-producing areas of the 
United States is shown in figure 1. With the opening of the great 
southern prairies of Louisiana and Texas for rice culture and its 
more recent development in Arkansas, the production of rice in the 
United States has increased enormously. Not less striking, however, 
have been the improvements in the methods of planting, harvesting, 
thrashing, and milling. 
Much has been written about the new agricultural schemes for pro- 
ducing the rice crop, but very little literature is available on the mill- 
ing processes now in use. It is the object of this paper to describe 
10832°— Bull. 330—16 1 
