What are onions?
Onions are bulb vegetables that are part of the allium family. They mostly grow underground and have a strong, pungent aroma known for making people tear up when cutting them. There are a lot of variety of onions, but the most common are red, white, and yellow onions that all have unique characteristics. Other vegetables in the allium family are green onions, shallots, chives, leeks, and garlic. All of these vegetables have a similar sharp flavor to varying degrees.
What do they taste like?
Onions have a sharp very pungent taste when raw, but become sweeter and milder in flavor when cooked. While there are differences in the three onion varieties we are talking about today, generally they can be substituted for each other when cooking.
Red: Assertive and strong when raw, more mild when cooked
Yellow: The middle ground, still very assertive when raw, but become sweeter when cooked
White: Best used raw with a mild, crisp flavor. Can also be cooked.
What to look for when buying?
Due to the long shelf life and aging process, onions are easily found year round in grocery stores. When picking out an onion at the store, look for a firm heavy for its size onion. Avoid any that have soft spots. Some bruising or discoloration on the outside is just fine.
How to choose between the three varieties?
Bulb onions can be used interchangeably in recipes without much fuss, however, here are a few rules of thumb for each:
Red: Best for pickling (due to bright vibrant color), grilled, or minced finely for a pop of color and flavor.
Yellow: Most universal when in doubt use yellow. best for caramelizing or sautéing. Can be used raw in small amounts.
White: Best used raw in salads and salsa's due to its crisp mild flavor. Can be used cooked as well or substituted instead of yellow for a milder flavor.
How To Avoid The Tears?
I'm going to be frank, there is no way to avoid the tears unless you wear full on goggles that prevent the offensive gasses from reaching your eyes. The best way I have found to help reduce tears is to keep the cut side of the onion on the cutting board as much as possible and to work quickly (and safely) avoiding the cut sides being exposed as much as possible.
Nutritional Benefits
While onions are not often thought of for their nutritional benefits, they are low in calories and offer small amounts of fiber, carbs, protein and vitamins such as A and B6. More recently research has gone into understanding the phytonutrients in onions that could provide antioxidant and anti-inflammatory properties.
