Steel-cut oats are whole grain groats (the inner portion of the oat kernel) which have been cut into pieces. They are commonly used in Scotland and Ireland to make porridge, whereas rolled oats are used in England, other English-speaking countries, and Scandinavia. They are sometimes named after the grade of cut, e.g. pinhead oats; steel-cut oats from Ireland are sometimes called Irish oats.
Steel-cut oats come in different grades depending on the size of the pieces: pinhead (the largest), coarse, medium and fine.
Steel-cut oats take longer to cook than instant or rolled oats due to their minimal processing, typically 15–30 minutes (less, if pre-soaked). The flavor of the cooked oats is described as being nuttier than other types of oats, and they are also chewier.