Real Food Encyclopedia | Oats

Oats are synonymous with breakfast in the U.S., but they offer much more than just a quick bowl of porridge. Oats (Avena sativa) are an important staple crop cultivated in temperate regions around the world, thanks to their resilience in climates where few other grains succeed.

These starchy grains were first wild-harvested and hand-ground by paleolithic hunters and gatherers around 32,000 years ago. Today, oats are rolled or crushed to make oatmeal, pulverized into flour or blended with water and strained to make oat milk, which is increasingly popular in baked goods and espresso-based beverages like lattes and cappuccinos. However, according to the Kansas Farm Bureau, 95 percent of the oats harvested in the U.S. are designated for use as livestock feed.

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Fun facts about oats:

  • Because oat starch creates a thick, sticky paste, it is sometimes used as a glue extender.
  • Between natural oils and starches that can hold a lot of water, hydrated oats are good moisturizers. Many skin products use finely ground oats to help soothe skin irritation and address conditions such as eczema, sunburn and heat rash.
  • Oats were introduced to the British Isles by the Romans, and oat flatbreads and biscuits (more commonly known as oatcakes) remain an essential feature of the Scottish national diet.

What to look for when buying oats

Depending on how they’re processed, oats can come in a number of shapes and sizes. The most common varieties are whole oat groats, steel-cut oats, rolled oats, quick oats and oat bran. Each requires different cooking methods and times.

  • Groats are whole oat berries with only the hull, the outermost indigestible layer, removed. With the bran (the fibrous coating of the berry) and germ (the embryo that develops into the plant) intact, grouts are both filling and extremely nutritious, but they also take the longest to cook.
  • Steel-cut oats are groats that have been chopped into smaller pieces but not flattened like rolled oats. Also known as Irish oats, they, too, contain the bran and germ, making them a good source of nutrients and fiber.
  • Rolled oats and quick oats are the most ubiquitous of the oat varieties. Rolled oats start as whole groats that are then steamed, flattened with a roller and dehydrated. Quick oats are similarly processed, but are steamed for a longer time period, rolled thinner and eventually chopped into smaller pieces after the dehydrating process, allowing them to cook quickly in the microwave.
  • Oat bran is just the fibrous coating of the oat berry (kind of like the shell or skin), which can be isolated when oats are milled for more processed foods. It can be used to add fiber and toasty flavor to foods or made into a porridge on its own.

When shopping for oats, first consider when and how often you think you’ll be eating them. Steel-cut oats have more fiber and nutrients than rolled and quick varieties, but they require a much longer cooking time, so may not be as convenient for a quick breakfast.

To get the best deal for oats, compare the price per ounce of different packages. Also consider purchasing them from bulk containers, if available. These unpackaged oats are typically a fraction of the price of the packaged and branded varieties. They should have a fairly nutty, sweet aroma; when buying from bulk bins, avoid if the smell is musty or unpleasant.


Because oats grow well in cool, moist conditions, they make an ideal off-season or winter crop for farmers in many areas. This makes them a valuable addition to farms that are looking to improve their soil health, as they can be an excellent way to keep living roots in the soil over the winter — minimizing erosion and keeping nutrients in the ground. Because of this, they are an important crop for regenerative farms, where farmers try to minimize chemical use and environmental disturbance by keeping a diverse agroecosystem growing throughout the year. Even on industrial farms that grow mainly corn and soy, oats are a good way to add diversity into crop rotations that would otherwise leave soil periodically uncovered and vulnerable to erosion.


Various synthetic herbicides, such as glyphosate, have been used for decades to aid in the drying and storing of cereal grains. For oats, other small grains and some legumes, it’s common practice for farmers to prepare fields for harvest by using these chemicals to dry out the crop and make it easier to process. This means that oats and oat products sometimes show elevated levels of the pesticides that farmers use as desiccants, though this may be changing, perhaps as a result of consumer demand. In a 2022 study, the Environmental Working Group found that glyphosate levels in breakfast cereal and other oat-based products had drastically declined compared to tests from 2018. That being said, glyphosate is still found in many commercially available products, albeit generally below levels that pose a risk to human health.

Organic oats contain significantly less pesticide residue than conventionally grown varieties (though they may pick up trace amounts through processing), and sometimes no traces of pesticides at all. If you’re concerned about pesticide residues and want to limit your exposure, seek out organic oats.


Oats are usually seeded in early spring and need at least six to 10 weeks of cool-season growth. They are generally harvested in mid to late summer when planted in the spring.

Oats grow best in cool, moist climates, which means they can survive in many northern areas where other grains don’t thrive. They are primarily grown as an early-season crop in the northern parts of the midwestern United States. In the southern regions where they can germinate in the fall, oats have proven to be a useful winter cover crop where winter temperatures do not become as cold. As climate change shifts growing seasons, the range where oats are a viable winter crop is increasing, making them an important part of climate-resilient crop rotations 

Eating oats


Oats are shelf-stable and, depending on variety, can last anywhere from six months to three years when stored properly. Generally, they should be kept in a cool, dry environment with a consistent temperature. Any sort of moisture or temperature change can accelerate the growth of mold.

Loose oats purchased from bulk bins should be removed from packaging and stored in airtight containers (preferably in a dry pantry or cupboard) in order to maintain quality and freshness. And although they have a long shelf life, time will ultimately affect taste, so try to eat any opened bags within one year.


When deciding what to make with them, it’s hard to not first think of oatmeal. Microwaving quick oats is a fast and convenient cooking method, but the less processed varieties (steel cut oats or groats) are best made on the stove top with boiling water. Remember not to over-stir: this can activate the starch, resulting in a gummy texture. Mixing in different fruits, seeds or nut butters can help jazz up the taste and texture of oatmeal.

If looking for something a bit different, overnight oats are a great alternative: Just soak the oats in dairy or non-dairy milk, mix in some seasonings and store in the refrigerator overnight for a cold and creamy breakfast treat.

Oats can be used in a number of ways in both sweet and savory applications.They can be incorporated into cookies, scones, crumb toppings, breads, bars, loaves and pancakes. They are also a nice addition to homemade granolas or cereal bars.

Savory oat recipes are abundant in many global flavors and cuisines. Dishes like oat upma take advantage of India’s pungent spices, incorporating onion, cumin, ginger, chiles, coriander, curry leaves and toasted nuts into a porridge of oats, split chickpeas and vegetables. They can also be used in place of other starches and grains, such as rice or quinoa.

If you enjoy oat milk in your coffee, it’s straightforward to make at home: Simply blend oats in water until the mixture is smooth, then strain out the solids and add a sweetener or flavorings of your choice.


Oats are known for their health benefits and contain many important nutrients, including phosphorus, thiamine, magnesium and zinc. Oats are also an excellent source of both soluble and insoluble fiber.

However, although the nutritional content of oats is similar no matter their form, their effect on blood sugar is not. Varieties that are less processed (oat groats, steel-cut oats) take longer to digest than the rolled or instant variety, and, as a result, have a lower glycemic index. This means that they can help you feel full and energized for longer, without the spike and resultant crash in blood sugar that comes from eating more processed carbohydrates. The soluble fiber in oats also makes them bulkier as they absorb water in the digestive system, which also helps you feel more full after eating them.

A large body of evidence suggests that eating oats may help lower risk of heart disease and Type 2 diabetes, while also supporting the gut microbiome and digestive health. Incorporating them into one’s diet can also aid in weight control by slowing down digestion and the rate of nutrient absorption.

Top photo by Evgenia Tiplyashina/Adobe Stock.