How to Caramelize Onions

Caramelizing onions adds rich sweetness to most any dish. Our test kitchen walks you through the simple technique of how to caramelize onions.

Slowly cooking onions draws out their natural sweetness as the sugar in them caramelizes. The result is sweet, tender, dark-brown onions that enhance the taste of just about anything, from soups to meats.

All you need is oil, onions and a little time. You can caramelize any onion, but some varieties might caramelize more quickly depending on their sugar content. Standard yellow onions work well and actually have more sugar than Vidalia and other sweet onions. (See here for more about onion varieties.)

More important than the type of onion you choose is how you prepare it:

  • Slice onions into consistent shapes and thicknesses to ensure they cook and caramelize evenly.
  • Onions will lose about 2/3 of their volume as their water evaporates during cooking, so start out with more than you think you need.
  • Watch the onions closely and stir frequently. As they near the end of cooking, you might need to stir every minute to prevent burning.

How to Caramelize Onions

Step 1

Slice root and top off onion; cut in half. Peel and slice. Use a large, heavy skillet so the onions are not crowded. Heat oil in the pan over medium heat; add the onions and stir to coat.

Step 2

Cook onions, stirring occasionally from the bottom every 5 minutes. Once onions begin to brown, reduce heat. Continue cooking 20-30 minutes, stirring every 2-5 minutes until onions are golden-brown, adding more oil if needed.

Step 3

When onions reach their desired color, remove from heat to stop cooking. Sprinkle onions with salt, pepper and sugar to enhance flavors if desired.

Jazz 'Em Up

Caramelized onions take on new personalities with these mix-ins:

  • Fresh or dried herbs
  • A splash of balsamic vinegar
  • A few tablespoons of red wine or beef broth

Add 'Em On

Onions this good make just about anything taste better. Try them with:

  • Mashed, baked or roasted potatoes
  • Steak, poultry or sausages
  • Scrambled eggs or omelets
  • Sauteed vegetables

Make extra caramelized onions to keep on hand in the fridge (3 or 4 days) or freeze (up to 3 months) to dress up soups, salads, sandwiches and dips in a flash.