Commercial milling systems mill the paddy in stages, and hence are called multi-stage or multi-pass rice mills. The objective of commercial rice milling is to reduce mechanical stresses and heat buildup in the grain, thereby minimizing grain breakage and producing uniformly polished grain. Compared to village-level systems, the commercial milling system is a more sophisticated system configured to maximize the process of producing well-milled, whole grains.

A commercial milling system.

Village-type rice mills can be found in rural communities and are used for service milling paddy of farmers for home consumption. In many cases, village mills are adaptations of the Engleberg coffee huller from the United States, modified for milling rice.

These mills, however, are notorious for breaking paddy grain. Because of the high breakage, the total milled rice recovery is 53-55%, and head rice recovery is on the order of 30% of the milled rice.

A village mill

Nowadays, many Engleberg mills are replaced by the single-pass compact rice mill. A typical compact rice mill consists of a small rubber-roller husker and a friction whitener. The two byproducts of the compact mill--husk and bran--are discharged separately. The milling performance of the compact rice mill is superior to the single pass Engleberg huller. Milling recoveries are normally above 60%.

A compact mill

The test mill is a small and portable mill designed to test samples of paddy rice for milling quality. A test mill might be used by a paddy rice buyer who wants to see how well a quantity of paddy rice mills before buying it. Test mills are also ideal for lab environments where small amounts of paddy rice need to be prepared for experimentation.

A rice test mill.