Whole oat groats

Closeup picture of whole oat groats.

“Groat” is another word for a grain kernel. Whole oat groats are basically raw oats stripped of hulls, which also means that it hasn’t been processed much. They can also be stored for about 10-15 years in ideal conditions (cool, dry place with little or no oxygen).

Due to minimal processing, whole oat groats digests slowly, which keeps you fuller for longer.

Great for: People who don’t mind the long cook time and want to make the most out of the chewy texture of well-cooked whole oats.

Cooking time: Longest of the lot. Typically an hour.

Texture when cooked with water: Chewy.

Recommended ways to prepare: Overnight in a slow-cooker.

Steel-cut oats

Closeup picture of steel-cut oats.

Also known as Irish oats, steel-cut oats are whole oat groats that have been roasted and chopped into smaller pieces.

The roasting happens at a low temperature, just enough to denature the enzymes that can cause oats to go bad. This makes the product more shelf-stable.

Chopping up the whole oats help to speed up the cooking process considerably while retaining the chewy characteristic.

Great for: People with less time, yet enjoy a nice bowl of chewy oats.

Cooking time: 20-30 minutes.

Texture when cooked with water: Chewy and coarse.

Scottish oats

Closeup picture of Scottish oats.

Scottish oats are neither rolled nor cut; they are ground by stone mills. The result is oatmeal that varies in texture, ranging from powder to bits of oats, which are definitely not as uniform in appearance as compared to steel-cut oats.

When made into porridge, Scottish oats produce a range of mouthfeel: the powdery oatmeal makes the porridge sticky, while the bigger pieces of oats retain its bite.

Great for: People who have some time on their hands, like their oats a little creamy yet still be able to chew on tiny bits of oats.

Cooking time: 10-15 minutes.

Texture when cooked with water: Creamy with bite.

Rolled oats

Closeup picture of rolled oats.

Whole oat groats are steamed to soften them before they are rolled into flat discs, forming rolled oats. This process also stabilises the oils in the oats, so that they stay fresh for longer.

Compared to steel-cut oats, rolled oats cook faster and absorb more liquid. They also hold their shape rather well during cooking.

Great for: People who have some time on their hands, like their oats a little creamy yet still be able to chew on tiny bits of oats.

Cooking time: 10-20 minutes.

Texture when cooked with water: Soft, chewy and slightly creamy.

Quick oats

Closeup picture of quick oats.

Quick oats are rolled oats that have been steamed longer and rolled flatter. The precooking and larger surface area help the quick oats to cook, well, quickly.

As opposed to instant oats, quick oats tend to have only one ingredient – oats.

Great for: People who want a quick bowl of stove-cooked oats with fresh ingredients and without the fuss.

Cooking time: 1-5 minutes.

Texture when cooked with water: Creamy and mushy.

Instant oats

Closeup picture of instant oats.

Instant oats are made to cook quickly in a microwave oven or with boiling water. They are quick oats that are steamed even longer and milled even finer. Instant oats are basically pre-cooked, dehydrated oat flakes.

Many instant oats come with other ingredients, such as sugar, creamer and flavouring.

Great for: People who don’t have much time and need their oat fix immediately.

Cooking time: 2-3 minutes.

Texture when cooked with water: Smooth and creamy.

Oat flour

Oat flour in a bowl.
Credit: Shutterstock

Because of how fine oat flour is, it is the fastest digesting oat of the lot.

Unlike the other forms of oats, oat flour is usually used as a complement to thicken soups or stews, or for baking.

Great for: Baking or thickening soups and stews.

Cooking time: negligible.

Texture when cooked with water: Smooth and creamy.