Onions Key Terms

Dig deeper into understanding onions with important onions key terms

By Heidi Crossman

The familiar potency and vibrant flavor of the onion is considered an essential foundation in many dishes. With many different kinds and each variety having its best use, it is beneficial to peel into onion knowledge a few layers deep instead of stopping at the skin. Knowing these vocabulary terms will develop confidence when choosing and using onions. Growers and chefs, as well as produce wholesalers and grocery retailers, can benefit from this information.

Blight

Blight is a fungus that damages the plant leaves and causes crop failure. You will know if your onions have been attacked by blight if the leaves gradually lighten to yellow then wither.
Try: PLANTanswers will aid in your learning more about blight. For photos of infected plants and ways to control the disease, visit Vegetable MD Online.

Purple blotch

A fungus that infects onions that is triggered by leaf wetness, purple blotch begins as a sunken white area and progresses to deaden the leaf above the infected area.
Try: Montana State University explains the disease in full with information on control and prevention.

Long-day, short-day

Onion varieties are split into long-day and short-day growing categories. The one you should choose depends on the growing conditions where the onions are planted. Growers in southern states should plant short-day varieties, which flourish where sunlight is apparent 12 and 14 hours a day. In northern states where summer days are longer, long-day onion varieties should be planted.
Try: For information on long- and short-day onions as well as growing tips, visit Oniongardening.com.

Propanethiol S-oxide

Propanethiol S-oxide is a gas agitated by the mixing of enzymes when an onion is cut. This is the gas that, when mixed with the water in our eyes, creates sulfuric acid. Our eyes react to the acid by activating tears in order to get rid of the acid.
Try: Everything2 explores the creation and dispersion of propanethiol S-oxide in onions in answer to the question, "Why does cutting an onion make you cry?"

Dry onions, green onions

Dry onions are recognizable in stores as a bulb only and come in white, red or yellow color. The flavor of these onions is as varied as the type you choose, differing in range from sweet to pungently spicy. Green onions are smaller and more mild and come with the leaf intact. Dry onions are the mature form of the green onion.
Try: To learn more about dry onions and green onions and recommended uses, see RecipeTips.Com.

Spring/summer onion, storage onion

Dry onions are either spring/summer onions or storage onions. Spring/summer onions include those that are grown in warm weather climates, have thin skins and have a range of mild to sweet tastes. Storage onions have a more pungent flavor and are typically grown in colder weather climates. After harvesting, these onions are dried out for several months, during which they obtain brittle skins. Storage onions are usually named in correlation with their color: white, yellow or red.
Try: Chow is a great resource for finding out more about the differences between these two types of onions and the best ways of handing and using each one.