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rick must be pulled down, aired and built afresh; but if the stake is not too hot to hold, the rick must be left undisturbed." 1
In the prairie regions the self-binding harvester is used. (164) Slow curing in the shade gives best milling rice. Shocks should be placed upon dry ground lengthwise east and west, and caps should be put on with heads towards the north in order to avoid the sun as far as may be.2 (161)
524. Threshing.—Rice is now universally threshed in the United States with the ordinary threshing machine. The itinerant machine (167) is used in the South Central States, but in the South Atlantic States stationary threshing machines placed under cover are employed, when they are referred to as threshing mills. Some care is required to adjust the machine so as not to break the grains.
525. Use.—The chief use of rice is for human food. It is estimated to enter into the dietary of more than one-half the population of the world, and is said to form more than fifty per cent of the subsistence of the people in some parts of Asia. In China it is used largely in connection with the fish raised so abundantly in their numerous waterways, and also with the soja bean (Glycine hispida Maxim.), which, on account of the high per cent of protein and fat in this bean, makes a diet resembling closely one made of meat, potatoes, bread and butter. Rice is usually eaten whole or in soups; it is seldom made into any form of bread or pastry, for which it is not well adapted, on account of its low percentage of gluten. It is sometimes, however, mixed with wheat flour. Rice is largely used for the manufacture of starch, and its lower grades are also used in the production of malt and alcoholic liquors. (465) The lower grades are so extensively used for this purpose as to be known to the trade as brewers' rice.
1 U. S. Dept. of Agr., Div. of Stat Misc. Ser. 6, p. »j » U. S. Dept. of Agr, Div. of Bot. Bui. 22, p. 29,
Rice straw is not highly prized as food for domestic animals on account of its lack of palatability, nor for bedding because of its coarseness. It is valued as manure for rice and other lands; the straw, together with roots and stubble, containing much the larger proportion of the ash ingredients of the plant. The so-called "rice straw" used for making hats and other articles is not rice straw but that of other cereals grown for that purpose. (490) The so-called "rice paper " of the Chinese
is made from the pith of a tree native to the island of Formosa.1
526. Preparation for Use*
—The paddy or rough rice is prepared for use first by the removal of the husk or hull, and next by the removal of the cuticle or bran; the bran in this case being analogous to the bran, middlings and shorts of wheat. After the cuticle and embryo have been removed the kernels are polished in order to enhance their glossy appearance. This is believed in no way to improve the nutritive value but rather to decrease it; however, it greatly improves its commercial value. The following is a detailed account of the milling process:s
"The processes of milling rice are quite complicated. The paddy is first screened to remove trash and foreign particles. The hulls, or chaff, are removed by rapidly revolving 1 milling stones 1 set about two-thirds of the length of a rice grain apart. The produce goes over horizontal screens and blowers, which separate the light
1 U. S. Dept. of Agr., Div. of Stat. Misc. Ser. 6, p. 15.
2 The Present Status of Rice Culture in the United States. By S. A. Knapp, U. S. Dept. of Agr., Div. of Bot. Bui. 32, pp. 34-35.
Rice, variety Honduras, showing steps in the milling process: I, rough rice, as it comes from the threshing machine, known as paddy; -2, same rice after it has been through the shelter, which removes husks or flowering glume and palea; 3, clean rice after it has been through either mortar and pounder or huller to remove cuticle and embryo, and through polisher to give it a highly finished surface. (After Bond.)
chaff and the whole and broken kernels. The grain is now of a mixed yellow and white color. To remove the outer skin the grain is put in huge mortars holding from 4 to 6 bushels each and pounded with pestles weighing 350 to 400 pounds. Strange to say, the heavy weight of the pestle breaks very little grain.
"When sufficiently decorticated, the contents of the mortars, consisting now of flour, fine chaff, and clean rice of a dull, filmy creamy color, are removed to the flour screens, where the flour is sifted out From thence the rice and fine chaff go to the fine-chaff fan, where the fine chaff is blown out and mixed with the other flour. The rice flour, as we call it, or more properly 'rice meal/ as our English neighbors call it, is very valuable as stock feed, being rich in carbohydrates as well as albuminoids.
"From the fine-chaff fan the rice goes to the cooling bins, rendered necessary by the heavy frictional process through which it has just passed. It is allowed to remain here for eight or nine hours, and then passes to the brush screens, whence the smallest rice and what little flour is left pass down one side and the larger rice down the other.
"The grain is now clean and ready for the last process—polishing. This is necessary to give the rice its pearly luster, and it makes all the difference imaginable in its appearance. The polishing is effected by friction against the rice of pieces of moose hide or sheepskin tanned and worked to a wonderful degree of softness, loosely tacked around a double cylinder of wood and wire gauze. From the polishers the rice goes to the separating screens, composed of different sizes of gauze, where it is divided into its appropriate grades. It is then barreled and is ready for market.
"In mills more recently erected the foregoing process has been modified by substituting the 'huller' for the mortar and pounder. The huller is a short, cast iron, horizontal tube with interior ribs and a funnel at one end to admit the rice. Within this tube revolves a shaft with ribs. These ribs are so adjusted that the revolution of the shaft creates the friction necessary to remove the cuticle. The rice passes out of the huller at the end opposite the funnel. It resembles externally a large sausage machine. It requires six hullers for each set of burs. The automatic sacker and weigher is used instead of barreling, sacks being preferred for shipping the cleaned rice. Sheepskins are used for polishing.
"With the above modifications of the milling processes considerable reduction has been made in the cost of the mill. Mills of a daily capacity of 60,000 pounds of cleaned rice can now be constructed at a total cost of $10,000 to £15,000."
Mills are now constructed suited to plantation use which combine all the operations in one machine, receiving the rough rice or paddy as it comes from the thresher and turning out clean rice ready for use. While the polish is not so high as in the more complicated processes, the product answers the requirement of rice eating.
In the preparation of rice for market it is important to have the grain remain whole, since if broken its commercial value is reduced about one-half. These unbroken kernels are known as head rice. Great variations exist in different varieties and different grades of rice in the proportion of head rice to broken rice, as well as in the total amount of milled rice produced from a given amount of paddy. No accurate figures can be given of the proportion of head rice to broken rice, but the following illustrates what may be obtained from 100 pounds of a good sample of rough rice: head rice, thirty-seven; slightly broken, nineteen; very broken, six; polish, three; bran, fifteen; hulls and waste, twenty pounds. While as high as fifty per cent or more of head rice may be obtained in some cases, in others none is obtained. The product of American mills is about as follows: clean rice, sixty; polish, four; bran, seventeen; and hulls and waste, nineteen per cent.1
527. By-Products.—The by-products of rice consist of hulls, bran and polish. The bran is properly composed of the cuticle (503) and the embryo, with a small mixture of hulls which it is not possible to prevent in the milling process. In practice, a
considerable quantity of hulls is mixed with the bran. This mixture, sometimes containing as high as seventy per cent of hulls, is usually referred to in commerce as rice bran, while when the bran
Characteristic ribbon-liks rows of cells .
in rice hulls, highly magnified, which is comparatively free from hull it serve to identify the ground hulls when js caned rice meal. Both the bran used as an adulterant. (After Street.) and the polish are also more or less mixed with small particles of broken rice, called grits. Rice hulls are not only of no value as food for domestic animals, but apparently are injurious. They are consumed at the mills as fuel and sold for packing breakable articles and for similar uses. They are also ground and sold as husk meal or star bran. The
1 Twelfth Census of the United States, Bui. 201, p. 4.
Louisiana Station recommends a standard for rice bran of not more than ten per cent of hulls to prevent its adulteration with rice hulls. Assuming pure rice bran to contain ten per cent of crude fiber and pure hulls to contain forty per cent, the percentage of adulteration of bran with hulls may be calculated by subtracting ten from the per cent of crude fiber found upon analysis and multiplying by three and one-third.1 The New Jersey Station calls attention to the characteristic cells of the hull arranged in several convoluted ribbon-like rows as an easy means of identifying ground hulls when mixed with other feed.2 The following table gives recent analyses by the Louisiana Station:
Rice bran, which is the chief by-product, is characterized by its high percentage of fat, which through fermentation frequently breaks up into fatty acids and glycerine, thus causing a rancid taste which makes the bran unpalatable to domestic animals. When fresh, however, the bran makes an acceptable food for all classes of domestic animals and it is especially useful for mixing with the more nitrogenous cottonseed meal. Polish has been successfully fed to cattle and pigs, but is more largely used for
1 La. Bui. 77, p. 440.
* N. J. Rpt. 1902, p. 130.
* Containing sixteen per cent hulls and twenty-five per cent grits.
* Containing twenty-two per cent grits.