Paired with a hot cup of coffee and a crossword puzzle, oatmeal is a classic breakfast choice—ahem, it has the Ina Garten stamp of approval—for good reason. It’s nutritious, filling, simple to make (overnight, even) and versatile to boot. But when it comes to choosing the oats you want to eat, you’re faced with quite a few options. Here, we’re breaking down the differences in steel cut oats vs. rolled oats, so you can waltz through the cereal aisle with ease.
What are oats, anyway?
You can’t talk about types of oats without understanding what oats are in the first place. All oats, whether steel cut or rolled, are a type of whole cereal grain. Individual oat grains are the edible seeds of oat grass, made up of the germ (the embryo or innermost portion), the endosperm (the starchy, protein-rich part that makes up the bulk of the oat) and the bran (the hard, fibrous outer coating). Before any processing takes place, the oat kernels are hulled the inedible husks are removed, and they become groats.
Steel cut oats (sometimes referred to as Irish oats or pinhead oats) are the least processed form of oats. They’re made by taking the oat groats and cutting them into two or three smaller pieces using a steel blade. They’re coarse, chewy and can be toasted before cooking for additional nutty flavor.
Rolled oats, aka old-fashioned oats, are slightly more processed than steel cut oats. After hulling, the oat groats are first steamed to soften the bran, then rolled into flat flake-like pieces under heavy rollers and dried until shelf-stable. They’re chewier than instant oats (the kind sold in a packet with dinosaur eggs, for example), but smoother and creamier than steel-cut oats.
What’s the difference between steel cut oats vs. rolled oats?
While they start as the same thing, steel cut oats and rolled oats are two very different ingredients.
TBH, steel cut and rolled oats are nutritionally almost identical. But because they’re less processed and coat that outer bran, steel cut oats contain more soluble fiber than rolled oats.
Quick refresher: The Glycemic Index is a relative ranking of carbohydrates in food based on how they affect blood sugar levels. At 52, steel cut oats are considered low to medium on the glycemic index, while rolled oats have a slightly higher glycemic index of 59. The difference is miniscule, but steel coat oats are slightly less likely to spike your blood sugar (an important consideration for diabetics).
Taste and texture
Sure, steel cut and rolled oats taste almost the same, but their textures are vastly different. When made into porridge, rolled oats have the thick, creamy oatmeal texture you’re probably familiar with. Steel cut oats are much chewier, with a toothsome texture and less creamy consistency.
When made into porridge on the stovetop, rolled oats will take about five minutes to cook. Prepared the same way, steel cut oats take much longer—about 30 minutes.
We wouldn’t say steel cut and rolled oats are interchangeable, but they can be used in similar recipes. Both are excellent as overnight oats and baked into cookies or bars, but rolled oats are superior in granolas, muffins, cookies and as crumble toppings. (Steel cut oats would be unpleasantly gritty in either case.)
Which oats are the healthiest?
Here’s the nutritional info for one 40-gram serving of steel cut oats, per the USDA:
4g fiber (2g soluble)
Compare that to the nutritional info for one 40-gram serving of rolled oats, per the USDA:
4g fiber (0.8g soluble)
TL;DR? Neither steel cut oats nor rolled oats are healthier than the other—they’re almost identical in nutritional value. The only notable difference is that steel cut oats are slightly higher in soluble fiber, which can increase fullness; may lower cholesterol and control blood sugar; and helps regulate digestion, per the Harvard T.H. Chan School of Public Health.
Like we said, oats are a good source of soluble fiber, which leaves you feeling satisfied post-breakfast. And that means they can potentially aid in weight loss and help control blood sugar and cholesterol levels. They’re complex carbohydrates, so they’re harder for your body to break down and they provide sustained energy.
For being plant-based, oats are also relatively high in protein, which will keep you from crashing (or raiding the snack cabinet) at 11 a.m. And if you choose your oatmeal toppings carefully, oats can be low in sugar and fat.
Not to mention, oats are technically a gluten-free grain. (Just read the labels to make sure the oats you’re buying weren’t processed alongside other gluten-containing ingredients.)
What are instant oats?
Instant oats, often labeled “quick oats,” are the most processed type of oat—they’re made like rolled oats but rolled even thinner so that they cook up lightning-fast (hence the name). Instant oats only take about a minute or two to cook, but they retain almost no texture and are much mushier than steel cut and rolled oats.
Still, plain instant oats—the kind you buy in a cannister—have the same nutrition profile as steel cut and rolled oats. They’re a fine breakfast choice, if you don’t mind a mushy porridge. Where things get dicey is when you start talking about pre-packaged instant oats, which usually contain added sugar. (Sorry, dino eggs.)
Which types of oats should you eat?
Since steel cut oats and rolled oats boast almost identical nutritional profiles (both are high in fiber, low in fat, heart healthy and filling), you should eat whichever oats appeal to you most. If you like softer, creamier oatmeal, choose rolled oats. If you prefer lots of chewy texture and nutty flavor, go for steel cut. As long as you choose toppings that are equally nutritious (like fresh fruit, Greek yogurt and nuts), you can’t go wrong.
And which oats should you not eat? We try to avoid sugary instant oatmeal packets in favor of less processed options…but they’re still higher in fiber than, say, a breakfast pastry.