Oats

About oats
The Oat (Avena sativa) is a species of cereal grain, and the seeds of this plant. They are used for food for people and as fodder for animals, especially poultry and horses. Oat straw is used as animal bedding and sometimes as animal feed.

Oats are often served as a porridge made from rolled or crushed oats, oatmeal, and are also baked into cookies together with wheat flour. As oat flour or oatmeal, they are also used in a variety of other baked goods and cold cereals, and as an ingredient in muesli and granola. Oats may also be consumed raw, and cookies with raw oats are quickly becoming popular. Oats are also occasionally used in Britain for brewing beer. Oatmeal stout is one variety brewed using a percentage of oats for the wort.

Oatmeal
Oatmeal is ground oat groats (i.e. oat-meal, cf. cornmeal, peasemeal, etc.), or a porridge made from oats (also called oatmeal cereal or stirabout, in Ireland). Oatmeal can also be ground oat, steel-cut oats, crushed oats, or rolled oats.

Rolled oats
Rolled oats are traditionally oat groats that have been rolled into flat flakes under heavy rollers and then steamed and lightly toasted. The oat, like the other cereals, has a hard, inedible outer husk that must be removed before the grain can be eaten. After the outer husk (or chaff) has been removed from the still bran-covered oat grains, the remainder is called oat groats. Oat groats are a whole grain that can be used as a breakfast cereal. Steel-cut oats are oat groats that have been chopped into smaller pieces and retain bits of the bran layer. Since the bran layer, though nutritious, makes the grains tough to chew and contains an enzyme that can cause the oats to go rancid, raw oat groats are often further steam-treated to soften them for a quicker cooking time (modern "quick oats") and to denature the enzymes for a longer shelf life.

Rolled oats that are sold as oatmeal usually, but not always, have had the tough bran removed. They have often, but not always, been lightly baked or pressure-cooked or "processed" in some fashion. Thick-rolled oats are large whole flakes, and thin-rolled oats are smaller, fragmented flakes. Oat flakes that are simply rolled whole oats without further processing can be cooked and eaten as "old-fashioned" oatmeal, but more highly fragmented and processed rolled oats absorb water much more easily and therefore cook faster, so they are sometimes called "quick" or "instant" oatmeal. Oatmeal can be further processed into coarse powder, which, when cooked, becomes a thick broth. Finer oatmeal powder is often used as baby food. Rolled oats are also often the main ingredient in granola and muesli.

Steel-cut oats
Steel-cut oats are whole grain groats (the inner portion of the oat kernel) which have been cut into only two or three pieces by steel rather than being rolled. They are golden in color and resemble small rice pieces.

Steel-cut oats are also known as coarse-cut oats, pinhead oats, or Irish oats. This form of oats takes longer to prepare than instant or rolled oats due to its minimal processing, typically 15-30 minutes to simmer (much less if pre-soaked). The flavor of the cooked product is described as being chewier and nuttier than instant oats.

Scottish Oats or Scottish Oatmeal are sometimes confused with steel-cut oats. Scottish Oats are steamed steel-cut oats that are then ground by stones into an oat meal.