Different Types of Oats

A guide to the different types of oats and how to use them from oat groat, steel cut, rolled, quick, instant and even oat flour, we cover it all! Also included are helpful tips on best uses for each oat type and best recipes.

Oats are a health food staple and the internet is full of incredible oat recipes. You may have found yourself wondering about the different types of oats though and the best kind for each recipe. This article not only explains that but also answers any other question you might have about oats.

What are oats?

Oats are a nutritious whole grain cereal used mostly for human consumption, animal feed and skin products. The scientific name for oats is Avena sativa. The oats we typically eat are actually the oat’s seed. Oats are mainly eaten as a breakfast porridge, in cold cereals, and in baked goods.

Types of oats

There are actually 8 primary types of oats but this article covers the 6 forms of oats eaten most often:

1. Oat groats – best used in animal feeds, long cooking stews and porridges (1 cup weighs about 185grams)
2. Steel cut oats (Irish oats) – best used in oat bakes, slow cooker oatmeal, Instant Pot oatmeal, meatloafs, overnight oats, porridge, and oat flour; 1 cup weighs about 180 grams
3. Rolled oats (old fashioned oats) – best used in baked goods, stovetop oatmeal, baked oatmeal, microwave oatmeal, granola, cereals, overnight oats, smoothies, energy balls, oat milk, oat flour or many other purposes; 1 cup weighs about 112 grams
4. Quick oats – best used in baked goods or microwave oatmeal; 1 cup weighs about 110 grams
5. Instant oats – best used as a quick breakfast cereal only needing hot water; 1 cup weighs about 100 grams
6. Oat flour – best used in baked goods; 1 cup weighs about 100 grams

The two types of oats not detailed in this article are Scottish oats and oat bran. Scottish oats are ground up oat groat that is made into a porridge consistency. Oat bran is the casing around the oat groat, not the oat groat kernel itself.

Notice how much more dense oats are in their original form than they are in the more refined forms? This impacts serving sizes and how they are used in cooking. All were weighed by me twice to assure consistency but weight can vary between different brands and products based on how exactly they are made, how fine the flour is, and other various factors.

Are oats gluten free?

Oats are not guaranteed to be gluten free unless they are labeled as “gluten free.” Oats themselves are gluten free, but since oats are often processed on machines that process other grains, grown, and transported with other grains containing gluten, most oats typically end up having small amounts of gluten in them.

If you have celiac disease, are cooking for someone with celiac disease, or are gluten intolerant be sure to seek out oat products that clearly state they are gluten free on the packaging.

Oat groats

Oat groats are the whole oat after being removed from the inedible hull (outer husk). Of all of the types of oats readily available, oat groats are the most complete unaltered form. Steel cut oats, rolled oats, oat flour and other oat varieties are either chopped, ground, steamed or otherwise altered from the original oat groat.

Oat groats are the most dense, weighing nearly double what the same volume of rolled oats weigh. A serving size of oat groats is only 1/4 cup of raw oat groat while a serving size for rolled oats is 1/2 cup. Because of this, they take longer to cook and absorb more liquid while cooking. The finer oats are chopped and/ or processed, the less time needed to cook.

Cooked oat groats have a nutty flavor, remain chewy and don’t become mushy like oatmeal does. For this reason, many people prefer to soak them overnight before using. They work well in stews, soups and long cooking porridges. Here are a few recipes:

• Oat Groat Porridge
• Oat Groat Beef Stew

Steel cut oats

Steel cut oats, sometimes called Irish oats, are oat groats that have been cut 2-3 times with a steel blade, as opposed to rolled oats, which are flattened. They are a minimally processed type of oat and typically retain some of the bran which gives them a firmer, chewy texture. Since they aren’t steamed, they also have nuttier flavor than more processed forms of oats too.

Since steel cut oats are minimally processed, they take longer for your body to break down and digest. This causes blood sugar not to spike as quickly as it would with more processed forms of oats. It also leads to a longer feeling of satiety. They also have slightly more fiber and are more dense than rolled oats but the difference in glycemic load and fiber is marginal.

Steel cut oats are best used in oat bakes, slow cooker oatmeal, Instant Pot Oatmeal, as filler for meatloafs, overnight oats, and stovetop porridge. They can be used for oat flour but take more time to blend and make twice as much since they are more dense.

They have a longer cooking time, typically taking half an hour to cook on the stovetop. Given this, baked oatmeal is a great use for them so you don’t have to pay attention to the oats during cook time. Here are a few steel cut oat bake recipes:

• Cherry almond steel cut oat bake
• Strawberry banana steel cut oat bake

Rolled oats (old fashioned oats)

Rolled oats, also known as old-fashioned oats, are made by lightly steaming oat groats and then rolling them flat with a steel roller. Steaming stabilizes the natural oils in the oat groat so the oats keep fresh for a longer period of time. Rolling makes them cook faster and makes it easier to use them in different ways.

Steaming and rolling makes this form of oats flexible and usable in many different ways. They are the most common type of oats in kitchens across the USA since they are the most versatile.

If a recipe simply calls for “oats” without specifying a type, it is usually safe to assume that rolled oats will work. Rolled oats take 10 minutes to cook on the stovetop, less than half the time that steel cut oats take.

Rolled oats are used in baked goods like cookies, muffins, and cobblers. They also work well as oatmeal and can be cooked stovetop, in the oven or even in the microwave. Rolled oats are also used in granola, overnight oats, smoothies, energy balls, or for many other cooking and baking purposes. They are also the best oats to use for oat flour and for oat milk.

Here are some of our favorite rolled oat recipes:

• Chocolate protein overnight oats
• Microwave oatmeal
• Peanut butter energy balls
• Salted chocolate coconut granola
• Banana oat smoothie
• Spinach pancakes

Quick oats

Quick oats are essentially oats that are steamed more to partially cook them and then rolled much thinner to make them cook even faster. Because they are more processed, your body processes them more quickly as well and they don’t keep you full as long as rolled and steel cut oats.

Quick-cooking oats are best used in baked goods and as oatmeal on the stovetop or microwave. Quick oats typically are ready after just 1-2 minutes of cook time on the stovetop or in the microwave.

The texture will not be the same but you can typically substitute quick oats for rolled oats in baked goods. In porridges, you would need to reduce the cook time. Here are some quick oat recipes:

• Berry oat bars
• No bake chocolate cookies (my childhood favorite!)

Instant oats

Instant oats are the fastest cooking and most broken down of all oat types. They are fully cooked and then dehydrated and packaged, often in single serving paper pouches of thinner flakes. Because of this instant oats can be cooked simply by adding boiling water to them and stirring.

As with quick oats, since the body can convert instant oats quickly to energy without much processing, they have a much higher glycemic load that steel cut or rolled oats.

Many instant oat varieties sold have preservatives, flavors, and sugars added. Flavors range from maple and brown sugar to berries and cream and everything in between. Since instant oats are normally meant to be eaten as is, I don’t have any recipes for instant oats to share.

Oat flour

Oat flour is simply oats ground finely enough that they become flour.

You can buy oat flour as is or easily make your own. Rolled oats are the easiest form of oat to make flour with since they grind quickly and keep well once converted to oat flour. Steel cut oats can be used too but need more grinding time.

Oat flour is more absorbent than wheat flour and cannot be substituted in baking without adjusting the quantity or making other adjustments to the recipe. That being said, there are many fantastic recipes that are specifically made to work with oat flour. Here are our favorites:

• Oat flour peanut butter banana muffins (a reader favorite!)
• Oat flour waffles
• Oat flour carrot muffins
• Oat flour banana almond butter muffins
• Oat flour pumpkin muffins
• Oat flour pumpkin protein balls
• Oat flour chocolate peanut butter cupcakes
• Oat flour chocolate chip cookies
• Oat flour buttermilk biscuits

Storing Oats

Oats come in many different containers at the grocery store including cardboard (think Quaker), plastic packaging, paper instant oat packs, mylar bags and various other forms. When they are steam processed (rolled, quick and instant varieties) typically have a much longer shelf life than raw oats because the steaming process removes the natural oils that cause oats to spoil.

Oats have have been known to have a long shelf life of over 30 years stored under the right conditions. BUT the oats you buy in store have a much shorter life span of 12 months to several years due to processing and packaging.

Keep an eye on the “best by” date and use your best judgement. Oats typically will become stale tasting but still be edible before they actually mold and go bad. Once oats are bad, they will taste sour and off. Sniff for the standard nutty oat smell, check for an off color, visible signs of mold, and bugs.

To extend the shelf life of your oats, consider storing them in a tightly sealing container (glass is best) in a dark cupboard.