Oat groats are oat kernels that have had the hulls removed. The hulls are the tough outer shell that protects the seed of the oat plant.
Steel-cut, rolled and quick oats all start out as oat groats.
Oat groats intended for human consumption are exposed to heat and moisture to make them more shelf-stable.
The oat groats are then processed in different ways to create either steel-cut, rolled or quick oats, all of which have distinct characteristics.
Also known as Irish oatmeal, steel-cut oats are most closely related to the original, unprocessed oat groat.
To produce steel-cut oats, the groats are chopped into pieces with large steel blades.
Steel cut oats have a coarser, chewier texture and nuttier flavor than rolled or quick oats.
They also take longer to prepare, with average cooking times varying 15–30 minutes.
However, you can soak steel-cut oats beforehand to reduce the cooking time.
Rolled oats, or old-fashioned oats, are oat groats that have gone through a steaming and flattening process.
They have a milder flavor and softer texture and take much less time to make than steel-cut oats, as they have been partially cooked.
A bowl of rolled oats takes 2–5 minutes to prepare.
Rolled oats can also be added to goods like cookies, cakes, muffins and bread.
Quick oats or quick-cooking oats are rolled oats that go through further processing to decrease cooking time.
They’re partially cooked by steaming and then rolled even thinner than old-fashioned oats.
They cook within a few minutes, have a mild flavor and soft, mushy texture.
Quick oats are not the same as instant, packaged oats that sometimes contain other ingredients like skim milk powder, sugar and flavoring.