Oats Processing: Milling

The single term ‘milling’ applied in the context of cereal, covers a wide range of processes. In general they are methods of transforming whole grains into forms suitable for consumption or for consumption into consumable products.

Oats are taken into the mill at harvest time from a select registered panel of local growers. The oats are then dried and safely stored until needed. When the oats enter the milling process, there are five distinct stages to this process:
1. Cleaning, drying and grading.
2. Dehulling and cleaning.
3. Groats to pinhead
4. Pinhead to oatlets.
5. Packaging and distribution.

1. The oats are brought at harvest into the mill by the growers. They are then cleaned and dried so that they may be safely stored until they are needed. When the oats enter the milling process, they are cleaned, taking off straws, stones and weed seeds and are then sent through a stream of air to remove any dust or light grains that would be unsuitable for milling.

Even high quality oat grain will require cleaning t ensure that only sound oats are processed.

2. The grain is then sorted by size into small grains, medium sized and large size grains. The Oats are then fed into the oat sheller, which cracks the husk off the grain without damaging the kernel.

Traditional oats mills used stones set at well defined distances to split the hulls and enable them to be detached from the groats. Although this procedure is still used in some smaller mils, the larger mils that are needed to produce the quantities of oat products required today use impact hullers.

The mixture of kernel and hull is fed into a stream of air which blows off dust and hull. It is then subject to a polishing which removes the dust and hull which has not been properly dislodged.

Hulls are by products of oat milling, and from these furfural is prepared which, with its derivatives, is used in making nylon, in oil refining and in some other industrial processes.

3. The groats are then cut by feeding them into a cylinder with a large number of holes, the kernel fall through these holes and are cut to produce what is called Pinhead oatmeal.

This is the oatmeal which can be used to make traditional porridge.

4. The pinheads are steam cooked at over 100 degrees Celsius before being rolled into oat flakes.

The majority of wholegrain oats that is destined for human consumption is either processed to oat flakes by roller mill or to cut grains by cutting the groats into 3-4 pieces by steel cutter.

The flakes are then dried, cooled and stored in containers for packaging.

5. The product is then automatically weighed, dropped in its packet, the packet is then pressed down, folded and sealed.

The packets are then packed into cartons ready for distribution.

Oats flakes can be used as such for baking processes, as they will disintegrate readily once mixed with water.

The flavor of oatmeal is largely determined by the preliminary killing of the grain, and its texture as a cooked food by the degree to which it is milled.

Oats are kilning with the objects of assisting milling operations, producing a desirable flavor and avoiding the occurrence of a type of rancidity commonly found in stored oatmeal.
Oats Processing: Milling