Hafragrautur

Oatmeal is a preparation of oats that have been de-husked, steamed, and flattened, or a coarse flour of hulled oat grains that have either been milled (ground), rolled, or steel-cut. Ground oats are also called white oats. Steel-cut oats are known as coarse oatmeal, Irish oatmeal, or pinhead oats. Rolled oats were traditionally thick old-fashioned oats, but can be made thinner or smaller, and may be categorized as quick oatmeal or instant oatmeal depending on the cooking time required, which is determined by the size of the oats and the amount of precooking. The oat grains are de-husked by impact, and are then heated and cooled to stabilize the groats, the seed inside the husk. The groats may be milled to produce fine, medium, or coarse oatmeal. Rolled oats are steamed and flattened whole oat groats. Old-fashioned oats may be thick and require longer cooking time. Quick-cooking rolled oats are cut into small pieces before being steamed and rolled. Instant oatmeal is cooked and dried, often with a sweetener and flavorings added.

Source: Wikipedia