How do you caramelize onions?

Ask Peggy

Ask Peggy

DEAR PEGGY: I really love French Onion Soup. However, I never seem to be able to get the onions to caramelize. What sort of onions should I be using? I've been using yellow onions and they never work. They just get very limp and stringy! Please help! —L. P., Fayetteville, Arkansas

Caramelizing onions requires low heat for a long period of time. This slow cooking process dissolves some of the strong sulfur compounds and breaks down the onions' natural sugar, resulting in mildly sweet onions that are deep brown in color. White, yellow and even red onions can be caramelized. Sweet onions caramelize especially well because of their high-sugar content.

To caramelize onions, saute 6 cups thinly sliced onions in 1 to 2 tablespoons of olive oil or butter (or 1 tablespoon of each) over medium heat for 15 minutes or until moisture from the onions has evaporated and the onions are wilted. Reduced heat to medium-low and saute 15 minutes longer. Add 2 tablespoons brown sugar. Cook and stir for 15 to 20 minutes longer or until onions are a caramel brown color. If the onions stick to the skillet, add water, 1 tablespoon at a time.