How To Caramelize Onions

Caramelized Onions
Elaine Lemm
  • 01 of 07

    Use a Sweet Onion

    Caramelized Onions Ingredients
    Elaine Lemm

    Gather your ingredients.

    Caramelized onions are not synonymous with grilled onions. Both have their place, and grilled onions can be delicious. But grilling is about high heat, and caramelization happens slowly, over low heat.

    Caramelization is a chemical change that makes carbohydrates (e.g. sugars) turn brown when heated to temperatures of 310°F or higher. The best onions for caramelizing are the so-called "sweet" onion varieties:

    • Vidalia (Georgia)
    • Walla Walla (Washington)
    • Sweet Imperial (California)
    • Oso Sweet (Chile)
    • Texas Sweet (Texas)
    • Mayan Sweet (Mexico)
    • Maui (Hawaii)
    Continue to 2 of 7 below.
  • 02 of 07

    Heat Oil in a Nonstick Pan

    Caramelized Onions Butter and Oil
    Elaine Lemm

    Let the oil get hot for a moment. If you like, you can use a mixture of oil and butter. Clarified butter is best, since it won't burn as easily as ordinary butter, but ordinary butter is fine too. As long as you follow my advice and don't let things get too hot, your butter won't burn.

    As long as we keep things at 310°–320 degrees, you can use practically any oil, even olive oil, which has a very low smoke point. But since it's hard to know the exact temperature, stick with butter or a combination of butter and vegetable oil. Coconut oil will work too. 

    Continue to 3 of 7 below.
  • 03 of 07

    Add Sliced Onions

    Caramelized Onions Cook
    Elaine Lemm

    Keep the onions moving around the pan at first so that they don't burn. They'll cook down quite a bit in volume, so it's OK if the pan seems overfull at the beginning.

    Continue to 4 of 7 below.
  • 04 of 07

    Onions Turn Translucent

    Caramelized Onions Translucent
    Elaine Lemm

    As you cook them, the onions will start to soften and turn translucent. The reason we use sweet onions is because they have a higher sugar content, and it's the sugar that is actually turning brown. But ordinary yellow onions have some sugar in them, and you can certainly caramelize them as well.

    Continue to 5 of 7 below.
  • 05 of 07

    Onions Soften as Moisture Cooks Out

    By this time the onions will have softened and cooked down to a fraction of their previous size, as the water in them has slowly cooked away. They'll also have a slightly sticky consistency. That's because of the sugars in the onions. Good stuff.

    Continue to 6 of 7 below.
  • 06 of 07

    Golden Brown Color Begins to Develop

    Caramelized Onions Browning
    Elaine Lemm

    See the golden brown color beginning to develop? You're well on your way to caramelized onion yumminess.

    Here's an idea. Get some puff pastry, spread a sheet of it on a baking pan. Brush it with butter, then top it with caramelized onions and chunks of brie cheese and bake until the cheese is melted and the pastry is puffy and golden brown. 

    Continue to 7 of 7 below.
  • 07 of 07

    The Caramelized Onions

    Caramelized Onions Finished
    Elaine Lemm

    Here they are — a rich, golden brown hue and bursting with smoky, sweet onion flavor. Need an excuse to throw a few burgers on the grill? Delicious caramelized onions like this are all the reason you need. Not to mention this classic French onion soup. Enjoy!