primarily done in food-grade plants, not in feed-grade plants. Groats are not considered raw if they have gone through this process; the heat disrupts the germ and they cannot sprout. Sizing of groats Some whole oat groats break during the de-hulling process so additional processing of the groats is required. Groats are sized again and separated by length and width using shaker screens and indent cylinders until uniform product streams are generated. Modern oat milling technologies also sort impurities by colour with colour sorting machines or more traditionally, on specific gravity with paddy tables or gravity table separators. A final grade of whole oat groats should have minimal oat hulls, other seeds or broken groats. When the whole oat groats are to be flaked for use in porridge, the whole groats are passed through a groat cutter machine to create uniform pieces of cut groats for quick or instant style porridge whereas traditional style porridge is flaked from whole groats. The small percentage of broken groats generated throughout the de-hulling process are also utilised in various other products or even in flaking for porridge. Final processing Three methods are used to make the finished product: Flaking This process uses two smooth cylinders rotating at a controlled distance, before which the cut groats are conditioned and then passed through the cylinders for flaking. Conditioning of the groats for flaking ensures production of stable and consistent flakes with minimal crumbling and is done by adding moisture and heat to the groats with sufficient retention time prior to flaking. Oat flake thickness is a key control point dependant of the type of oat flakes to be produced which typically range from around half a millimetre for quick or instant style porridge and up to around 1mm for traditional style porridge. After flaking, the oats are then dried to a sufficient moisture for storage and transport. Oat bran milling This process takes the oat groats through several roll stands to flatten and separate the bran from the flour (endosperm). The two separate products (flour and bran) get sifted through a gyrating sifter screen to further separate them. The final products are oat bran and debranned oat flour. Whole flour milling This process takes oat groats straight to a grinding unit (stone or hammer mill) and then over sifter screens to separate the coarse flour and final whole oat flour. The coarser flour is sent