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How to Perfectly Caramelize Onions

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Melanie is an avid vegan homemaker who has been enjoying cooking and experimenting in the kitchen for over 15 years.

Caramelized onions are a thing of beauty.

Caramelized onions are a thing of beauty.

How to Caramelize Onions

As the old proverb goes, patience is a virtue, especially when it comes to making caramelized onions. Cooking the onions in this manner allows their natural sugars to come out, leaving them deliciously sweet and with a mild onion flavor. They are an incredibly versatile ingredient, making them a food staple, at least in my kitchen. Of course, they are well known for making French onion soup; however, they are also excellent in sandwiches, quesadillas, pizzas, casseroles, etc.

Important Notes on Caramelizing

  • When cooking the onions, it's imperative that proper time is taken to allow the natural sugars to be extracted slowly so they don't burn.
  • Equally important is allowing the onions to sit and caramelize. This means stirring is not a frequent occurrence and should only be done every ten minutes or so to make sure the onions are not burning.
  • Make sure that you have a squeeze bottle full of water readily available because from time to time you'll need to deglaze the pan as they cook. The little crusty bits that collect on the pan are called "fond." This is where the flavor lies, so it is crucial that the pan gets deglazed with water so all of that lovely flavor does not get lost. Deglazing is also what will give the onions their beautiful brown color during the cooking process.

What Type of Pan to Use

Just as important as deglazing is making sure you don't use a non-stick pan. If you use a non-stick pan, the sugars will not be able to stick to the pan and create the proper caramelization needed for this process. Certainly, I would also recommend doing research on non-stick pans because they are terrible for your health. The Teflon coating has been linked to many diseases such as breast cancer, prostate cancer, liver tumours, and reduced fertility. Here's a great article that explains many of the dangers of Teflon.

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Read More From Delishably

I have always used a cast iron pan for this purpose, but if you have a pan that is stainless steel or copper, those would also work great. I would also suggest the use of a wooden spoon or spatula, especially if using cast iron. This will allow you to not scrape up your pan and ruin it.


  • 2 to 3 medium onions, halved, then 1/4-inch slice
  • 1 tablespoon avocado oil
  • 1 teaspoon salt
  • water, as needed


  1. Begin by heating your pan over medium-high heat and adding in the oil. Add in the onions, then the salt, and give them a good toss.
  2. Reduce the heat to medium or medium-low, depending on your stove, and allow the onions to cook. This will take some time, about 1 1/2 hours, so don't rush the process. The heat should be high enough that you can hear the onions sizzling, but low enough that you can leave them undisturbed for 10 minutes without having them burn. This will require a bit of monitoring at first to assess how they are cooking, but once you get the hang of it, it really is quite a hands-off process.
  3. Every now and then, you will notice that the pan is building up with fond. That's when you would take your squeeze bottle and put a bit of water in the pan to deglaze. When the water hits the pan, it's important to stir the onions and scrape up whatever you can from the bottom of the pan. Don't add too much water; you don't want to start steaming the onions. Just add enough to allow the fond to break off the pan and start coating the onions. I would say probably 1 to 2 tablespoons at a time.
  4. When the onions are finished cooking, deglaze one final time to make sure all the fond is removed from the pan. Stir the onions well and evaporate any water, then remove them from the pan.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2019 Melanie

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