When we think of oatmeal, we typically picture good old-fashioned rolled oats (or maybe quick oats). When you visit the store, especially our store, you find many varieties that may make you wonder what the difference is between them. What makes steel cut different from rolled? What makes instant different than quick? What makes Scottish different than Irish? Here’s a handy little explanation that will *hopefully* clear up any confusion.
Oat Groats:
I just love that groat rhymes with oat! The groat is the de-hulled oat grain. Some grains are called berries, but oats are known as groats. Quite simply, the most intact form of the grain available in the market. Use this version of oats as you would other whole grains. Oat groats are a bit softer than wheat berries and make a wonderful addition to pilafs and soups. We have some wonderful recipes using oat groats, such as this Creamy Mushroom and Grains Soup- a favorite at my house!

The oat groat is the whole oat kernel with the hull removed. Photo borrowed from culinate.com.
Rolled Oats:
The most common form of oats, rolled oats are made from oat groats that have been steamed to allow them to pass through the roller mills without cracking and breaking. Rolled oats are available in many different varieties, each of which refers to the thickness of the flake and cooking time required. The smallest and thinnest oat product is Instant, followed by Quick Cooking, Regular (Old Fashioned) and Extra Thick.
Instant oats have also been pre-cooked to make them truly instant. Just add hot water and you’ll have oatmeal. Most brands add sweeteners to their instant oats, but ours are simple, plain oats.
Most recipes calling for rolled oats are referring to quick cooking or regular, but using extra thick will add an extra chewiness that some find quite appealing.

The most common oat product, rolled oats are flat flakes.
Steel Cut Oats:
Steel Cut= Pinhead= Irish Oats. Steel cut oats are made from whole oat groats that have been chopped into two or three pieces, making for a much chewier cereal. They are almost exclusively used for breakfast, as they do not soften very well in baking applications. These are the oats used in the Golden Spurtle World Porridge Making Championship and you will find that they are cooked prior to being used in any recipes. You can find many wonderful recipes on the Golden Spurtle website, as well as our own, using steel cut oats.
What makes steel cut oats particularly attractive for breakfast, and the reason we tout them as the perfect fuel for your day, is how the body breaks them down. Because of their size and shape, the body breaks them down more slowly than rolled oats, preventing spikes in blood sugar and keeping you full longer.

Steel Cut Oats are much larger pieces than Scottish Oats
Scottish Oats:
The true oatmeal, Scottish oats are ground on our stone mills from whole oat groats. They are not rolled, they are not cut, they are ground. The texture of Scottish oatmeal is fairly fine, though more coarsely ground than flour. In the United Kingdom, this is what they imagine when you say oatmeal. In the United States, this is what we imagine when we use the term porridge. It’s creamy, thick and almost instant when combined with boiling water. This is what people would have made hundreds of years ago, before modern roller mills were invented.
Scottish oats are wonderful for baking, as they are truly a more coarsely ground flour- like cornmeal. Oatmeal, cornmeal, flaxseed meal- get it? Meal is the next grind up from flour and below farina. We have some great recipes on our site using Scottish oatmeal, including one of our favorites- Scottish Oatcakes.

Scottish Oatmeal is very finely ground. Photo borrowed from recipetips.com
I hope this has helped answer the question of what makes each variety different. If you’ve still got a question or two, please leave it in the comments and I’ll find you an answer.