How to Make Caramelized Onions: 11 Steps (with Pictures)

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How to Make Caramelized Onions: 11 Steps (with Pictures)
How to Make Caramelized Onions: 11 Steps (with Pictures)

Want to make any dish even more delicious in a very simple way? Just follow the trick of experienced cooks and add some caramelized onion! Start by chopping the onions into very thin slices and slowly sauteing them over a low heat with a little butter. The longer it cooks, the softer and sweeter they get, so no rush. Then, just mix them with the sauce, pasta or soup of your choice.


  • 2 large peeled onions (about 500 g).
  • 2 tablespoons (30 g) of unsalted butter.
  • Coarse salt to taste.

Makes about ½ cup (100 g).


Method 1 of 2: Caramelizing Onions on Stove

Make Caramelized Onions Step 1

Step 1. Cut the onions into thin slices

Put the peeled onions on a cutting board and cut them in half lengthwise, removing and discarding the bottom end. Then rest the flat side on the board and, with a sharp knife, cut them into thin slices 0.5 cm thick. Be careful not to cut to the roots so that the onion does not fall apart. After you finish slicing it, remove the root and discard.

Use the onion of your choice, such as purple or white

Step 2. Heat the butter in a skillet until it starts to sizzle

Place a deep skillet over medium heat with 2 tablespoons (30 g) of unsalted butter. Wait for the butter to melt and continue cooking until it starts to make noise.

It is important to use a deep skillet so that the fat does not spill or the onions do not jump out of the pan when stirring

Step 3. Gradually add the onion slices and add a pinch of salt

Put a handful of onions in the skillet and allow them to wilt for a minute. Continue adding the rest of the slices slowly, letting each slice soften a little for easier mixing. When adding everything, finish with a pinch of coarse salt.

  • If you put all the chopped onions in the pan at once, it's hard to stir them and the slices on the bottom cook faster than the ones on top.
  • It's okay to put all the slices in the pan at once to caramelize just one onion.

Did you know?

Even if you put the prepared onions in the oven, you need to stir the pan as well. In addition, they are more at risk of drying out and burning at the ends.

Make Caramelized Onions Step 4

Step 4. Cook the onions for 15 to 20 minutes so that they are lightly caramelized

Lower the heat and stir the slices every two to three minutes during this period. When they turn slightly brown, you can already put out the fire. It all depends on your preference.

Use them to make the classic French onion soup recipe, or continue to saute the slices to make them even softer and more intense

Step 5. Saute for another 15 or 30 minutes if you want them to be darker

To make caramelized onions softer and sweeter, keep stirring frequently until the slices are darker and browner, which takes another 15 to 30 minutes.

If they start to stick to the bottom of the pan, add 2 tablespoons (30 ml) of water or vegetable stock

Make Caramelized Onions Step 6

Step 6. Use caramelized onions in sauces, pastas or omelets

Add a few slices to scrambled eggs or pasta such as carbonara. If you want to make a sauce or caramelized onion paste, wait for them to cool before adding them to the sour cream and other seasonings in a blender.

To store leftovers, place them in an airtight container in the refrigerator for up to a week

Method 2 of 2: Trying Other Options

Step 1. Add balsamic vinegar and brown sugar for a more intense flavor

Try the onion towards the end of the preparation and decide if you want a slightly sweeter taste. If so, add 1 tablespoon (10 g) of brown sugar and 2 teaspoons (10 ml) of balsamic vinegar. Finally, finish cooking the onions until they are soft and caramelized.

Don't have brown sugar at home? Replace it with refined sugar and add 1 teaspoon (5 ml) of molasses

Step 2. Cook the onions in beer or cider to make them thicker

To serve caramelized onions with sausage or roast beef, how about adding 1 cup (240 ml) of beer or cider after cooking them for about ten minutes? Bring the liquid to a boil and then lower the heat to finish the preparation for another 20 minutes.

Beer or cider evaporates during the process

Step 3. Add a pinch of baking soda to speed up caramelization

If you don't have a lot of time, add a pinch of baking soda as soon as you finish putting all the slices in the pan. Baking soda raises the pH of the onion, which makes it brown faster.

Use ¼ teaspoon (1.5 g) of baking soda for every 500 g of onion

Step 4. Add thyme if you want a touch of freshness

Use a sprig of fresh thyme for each onion. Remove the leaves and add them to the skillet along with the onions. Mix well and finish caramelizing the slices.

Use the herbs of your choice to create different flavors. For example, chop fresh rosemary or sage leaves

Make Caramelized Onions Step 11

Step 5. Caramelize the onions in a slow-cooking crockpot if you don't want the trouble of stirring them

Fill at least half of the pan with onion slices and add 1 tablespoon (15 ml) of olive oil or butter for every 500 g of vegetable. Cover the pan and set a low temperature to let the onions cook for ten hours. Thus, they are golden and soft.

You can even stir the onions once in a while so they cook evenly, but it's okay to leave them in the pan without interference


if you prefer the slices to be tastier and thicker, remove the lid from the crockpot and let them cook for another three or five hours.


  • Double or triple the recipe amounts to make a larger portion.
  • Stuff your sandwich, hamburger or hot dog with caramelized onions.

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