Red onions are a bulbous vegetable that belong to the Allium cepa species. The outside skin of these onions is actually a shade of purple, while the insides are white with a hint of dark red, turning slightly blue when heated. They have a sweeter, milder taste compared to yellow and white onions but can still be pungent depending on their size and how they are prepared.
Although the first red onions are thought to have grown in Asia, they are now cultivated in most regions of the world. As people began to grow and harvest the onions, they came to realize that they last for an extended period of time without rotting. On average, a red onion can generally be stored for at least one month without any signs of deterioration.
There are several different types of red onions. The red beauty onion is a variety of small red onion with a rounder shape than other types, which gives it a shorter growing time. The pungency level of a red onion can also differ depending on the onion type. For example, the flamenco red onion is generally considered much more pungent than other types, while the red wing red onion is recommended for people who want a much milder onion taste. One type of red onion, the burger master, is actually genetically engineered to be larger than average and one slice is often the same size as a hamburger patty.
When red onions are eaten raw, they can have a sharp taste that some people may find overpowering. To reduce the sharpness and make the onion more palatable, it can be sliced and soaked in cold water for about 10 to 20 minutes to mellow out its flavor. If the onions are cooked, they release their natural sugars and have a sweeter taste.
The red onion is generally considered one of the more versatile types of onions because it can be served raw or cooked, as well as be paired with sweet or savory ingredients. For example, red onion is often combined with mango or apple-based dishes in addition to meats or vegetables. It is also often favored over yellow or white onions for presentation purposes simply because it is more colorful. When used raw, it is typically added to salsas, chutneys, salads, and on sandwiches. If the onions are grilled or roasted, they can stand alone as side dishes or be used in soups, casseroles, or other hot entrees.