Oat groats are the whole seeds of the oat plant, and are usually sold with the hull removed, but the bran and other parts intact. The best oat groats are consistent in size and shape, with a light brown surface and few broken grains. Avoid oats with a sour or waxy smell, as they may have gone rancid, as well as bags that contain a lot of dust or any web-like material, since these features indicate possible poor handling and the presence of flour moths. If you intend to sprout your oats, choose packages labeled specifically for this purpose, as other oat groats may have been heat treated for longer shelf life. These minimally-processed oats provide the most nutrients and lowest glycemic index of any type of oats, but preparing oat groats takes longer than cooking rolled or cut varieties.
Whole oats are uncommon in most grocery stores, which focus on instant, rolled and sometimes steel-cut varieties, but you may be able to buy them from health food stores or directly from a farmer. Groats may be sold pre-bagged or in bulk, with bulk oats being the least convenient but offering the freshest and least expensive option. If you choose pre-bagged types, check for an expiration or bagging date to ensure the best product.
Like other whole grains, oat groats can go rancid when exposed to warm temperatures or direct sunlight due to the oil that they contain. Rancid oats smell and taste a little sour, or slightly musty and waxy, and don't have the same nutritional value as fresh oats. Avoid any groats that have been stored close to a window or heater, and keep your oats in an airtight container stored in a cool, dry location.
Oat groats should all be about 1/8 inch long (0.25 cm), with an oval shape and a thin, light brown bran layer. Grains of a consistent size and shape cook more evenly than broken ones or a mix of very small and large groats, which may come out mushy or crunchy. If the bag contains a large percentage of broken oats or oat dust, it may have been handled very roughly. If you see any cottony or web-like material in a bag or bin of oats, avoid them, as this indicates that they may be infested with flour moth larvae.
Sprouted oats provide a little extra nutrition, but not all groats will sprout correctly. Look for packages labeled specifically for sprouting, since these will not have been heat-treated to stabilize them and increase storage time. Soaking oat groats for sprouting takes about 8 to 12 hours, after which they can be grown further or eaten immediately.
Most oats are eaten as hot cereal, but cooking oat groats requires a little special care, as these unbroken grains are tough and require long cook times. Consider soaking your groats overnight or preparing them in a slow cooker to make the process easier. You can also use sprouted or unsprouted groats in breads and other baked goods.