Oats are one of the most recent cereal grain to be domesticated, estimated at ~2500 BCE in Bronze-age Europe, and grew wild (considered a weed) in cultivated fields of various other crops.(1)
Oats have a long history of use as animal feed, but in Scotland it has been a staple and used as a porridge, or part of muesli in Nordic and Baltic regions of Europe. Unlike other cereals, oats can go rancid rather quickly so require immediate processing after a harvest.(2) They also almost never have their bran and germ removed, so they are always whole grain.(3) Oats are gluten free — if not processed in a factory that also produces gluten products.(4) Accounts are still that only ~5% of oats are for human consumption.
Health bonus: Scientific studies have concluded that like barley, oats contain a special kind of fiber called beta-glucan found to be especially effective in lowering cholesterol. Recent research reports indicate that oats also have a unique antioxidant, avenanthramides, that helps protect blood vessels from the damaging effects of LDL cholesterol.(5)
Steel-cut oats, or Irish oats: These are the entire oat kernel that has been chopped into small pieces. They have a firm, chewy texture and make a great breakfast porridge or oatmeal. (The image above shows steel-cut oats on the right.) This is my favorite to eat.
Rolled oats, or old-fashioned oats: These are oat groats that are steamed and flattened for quicker cooking. I use this for cookies, breads, and seed crackers. (The image above shows old-fashioned oats on the left.)
Quick oats: These are groats that have been cut into several pieces before being steamed and rolled into flakes, thus cooking faster. The flatter the oats are rolled, the faster they cook.
Instant oats: Instant oats are made by chopping oats into tiny pieces, cooking, drying, and finally flattening them with a roller. All you need to do is open a package of instant oats, add hot water, and you have an oat mash. However, they taste like paste to me, even with the “flavorings” and added sugars and salt they package with the food.
Oat flour: Oat flour is gluten-free and made from oats that have been ground into a powder. DIY Make your own flour by grinding rolled oats into a powder.