Harvesting and drying
Peak grain quality occurs at harvest. Care must be taken during the subsequent steps to preserve these quality characteristics in order to meet the high quality standards demanded by domestic and international processors as well as consumers.
 

Figure 27. Typical self-propelled rice combine.

California rice is harvested by large, self-propelled grain combines and dried on the farm or in commercial dryers. Two types of harvesters are used. The most common is the combine, which cuts the entire plant and separates straw from grain internally (fig. 27). The other, which is much faster and more efficient, is the stripper harvester, which uses a toothed rotating drum to strip grain off the stalk. The stalk remains standing in the field. Maintenance of milling quality during harvesting and drying is a major consideration because value is based on quality. Short- and medium-grain varieties are generally harvested at 20 to 24 percent moisture content and long-grain varieties at 18 to 21 percent moisture (fig. 28).

Figure 28. Optimum moisture content at harvest varies by grain type. Long grain varieties have a narrower region for optimal yields.

High moisture grain does not allow maximum kernel development and requires excessive drying costs. However, grain which is allowed to dry down in the field before harvest may reabsorb water during periods of high nighttime humidity and develop hair cracks, which reduces grain quality and value. Mixing grains of unequal harvest moistures may also result in fissuring. The relationship between grain moisture at harvest and total milled rice and head rice for a typical standing crop is shown in fig. 29.

Figure 29. The relationship between grain moisture at harvest and total milled and head rice for short and medium grain rice.

Once rice is harvested, it must be dried carefully to a storable moisture of 12 to 14 percent. Wet paddy rice is dried in column or bin dryers with heated or ambient air. At large commercial dryers, the grain is typically passed through the heated column dryer twice. The nearly dry grain is then moved to bin or flat bed storage facilities where it is dried to 14% moisture. Bin dryers are frequently used for on farm drying and storage.
Milling, marketing, and distribution
California rice is milled and marketed through grower cooperatives and independent millers. Paddy rice is transported to the mill and hulled to produce brown rice. Mills remove the bran to produce white rice. Price to the grower is principally based on the milling yield from 100 pounds of paddy rice, which includes head rice (the percentage of unbroken whole kernels) and the sum of head rice and broken rice (total rice); mill by-products add to the overall market value of rice (fig. 30).

Figure 30. One hundred pounds of rough or paddy rice yields 80 pounds of brown rice and about 55 pounds of whole white rice (also known as head rice).

California rice enters the market as quality table rice, processed foods, and mill by-products, including brewers' rice. Fifty to seventy percent of California's rice is used domestically, and the remainder is exported to the Pacific Rim, Europe, the Middle East, and elsewhere.

Although the United States produces less than 1.5 percent of the world's rice crop, it contributes 18 to 20 percent of the rice moving in world trade. Most export rice is for cash sales, but government-assisted exports of California rice have helped meet the needs of countries faced with food shortages due to crop failures and other disasters. In contrast to a per-capita consumption of rice in the United States that increased to over 22 pounds per capita in the 1990's consumption in many Asian countries exceeds 300 pounds per capita, where rice supplies over 40% of the calories in the average diet. Although over 90% of Asian rice is consumed where it is grown, Asia's increasing population and limited land resources increase the likelihood that California rice will continue to play an important role in international trade. However, per capita consumption has been decreasing in Japan, South Korea and Taiwan, where consumers are diversifying their diets away from rice. Within the last decade a number of Asian countries, Australia, and several Central and South American countries have become net exporters of rice, thereby increasing competition for US rice products in Asian markets.

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