How to Caramelize Onions

If, in the 9 years that I’ve been teaching myself to cook, there has been more of an elusive food for me to make, it has been caramelized onions.  Every single time I attempt to make them, they come out differently and since I love them so dearly, I want them to be perfect every.single.time.  Sometimes I add sugar, sometimes I don’t.  Some recipes say they only need to be cooked for 20-25 minutes (or amazingly less than 10); others state 40-45 – or, do I just wing-it?  Non-stick, cast iron, or stainless?  Don’t fuss with the onions while they cook or stir often?  White or vidalias?  Butter or oil?  Or both??

Seriously, could cooking onions not be more freaking difficult?  So I decided recently that it was time to really buckle down and tuck this kitchen staple under my belt.  This recipe is simple – as it should be for something as basic as onions – but it requires some patience.

How to Caramelize Onions

I’m not hugely picky about how I slice my onions but Cook’s Illustrated is (surprised?) so I sliced each onion in half through the root and chopped off each raggedy end.

How to Caramelize Onions

I then spun the onion half 90 degrees and made 1/4-inch slices.  No stringy onions in this house.

How to Caramelize Onions

You’re going to start with way more onions than you think you may ever need – 2 pounds, sliced is a lot of onion slices.  And yes, you’ll use both butter and oil.  The best of both worlds here.

It turns out that they really do take 45 minutes to cook, if you want them butter-soft, dark golden brown, and richly flavored.  You’ll need to have a good handle on the heat of your stove and you’ll want to make sure you do actually stir them often, especially towards the end of the cooking time.

How to Caramelize Onions

And for the love of all things good, let them cook.  After 25 minutes or so, you’ll think they are done (top photo on the page) but don’t be hasty and rush them.  They’ll be really browned and soft but trust me – they will withstand another 20 minutes in the pan.  You want the onions to have almost no bite left, for them to feel almost sticky, and for the color to be a really, really deep and delicious brown (last photo on page).

Once you feel like they are starting to stick to the pan, take them off the heat.  Your glorious caramelized onions will be done and you can beam in the light of their perfection.  Or wait.  Is that just me?  Use them on burgers, steak, hot dogs (uh, heck yeah), grilled cheese, in pasta dishes, fritattas, quiches, or tartlets (just to name a few).  I have a few new recipes ideas that use up these onions which I’ll share with you in the next couple of weeks so stay tuned…

Caramelized Onions

Prep Time: 10 minutes

Cook Time: 45 minutes

Total Time: 55 minutes

Yield: 1 cup caramelized onions


  • 1 tbsp unsalted butter
  • 1 tbsp vegetable oil (canola, grapeseed, safflower)
  • 1/2 tsp table salt
  • 1 tsp light brown sugar
  • 2 lb large white onions, root end cut off, halved pole to pole, peeled, and sliced 1/4 inch thick across the grain
  • 1 tbsp water
  • Ground black pepper


  1. In a 12-inch skillet, heat butter and oil together over high heat until the butter is melted. Stir in the salt and brown sugar until the sugar dissolves. Stir in the onions and mix them up to coat them with the butter and oil. Cook onions for 5 minutes, stirring occasionally, until the start to soften.
  2. Reduce the heat to medium and cook, stirring frequently (and even more so towards the end), about 40 minutes. The onions should be very deep golden brown in color and should be almost completely soft when tasted. If the onions are browning too fast or starting to burn, reduce the heat. You'll need to keep a close eye on them towards the end of the cooking time as they can easily burn at this point.
  3. Off the heat, stir in the water and season with black pepper to taste. Store for up to 1 week in an airtight container in the refrigerator.


source: adapted from The Cook's Illustrated Cookbook


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  • March 6, 2013 at 10:25 AM

    Thank you for this! My boyfriend and I are OBSESSED with caramelized onions and I always had results vary each time I made them.

  • March 6, 2013 at 10:45 AM

    whoa, these look very impressive! i always have the most success with caramelized onions when cooking alot & using a big pan, so your tips make sense!

  • March 6, 2013 at 11:57 AM

    Yep, this is one I’ve yet to conquer myself. I’m likewise determined and, thanks to your push, will take this on today!

  • March 6, 2013 at 2:15 PM

    Yeah…I could eat those directly from the pan, hovering and hoovering over the stove.

  • March 6, 2013 at 3:57 PM

    I will be trying his recipe thank you . I am guilty of peaking at your blog and not leaving a comment. I then moan that nobody comments on mine so think I am learning a lesson here .

    • March 6, 2013 at 6:44 PM

      Ha! Funny! We all moan about nobody commenting but if you don’t comment, we’ll never find out about so many blogs out there! Thanks for commenting. 🙂

  • March 7, 2013 at 11:39 AM

    I never realized it, but I totally make caramelized onions a different way every time too! Yours look so good – next time I’m making them, I’m coming back here! These are great instructions. My favorite way to use them is in a ham, brie, and caramelized onion sandwich on good sourdough. Oh my gosh, when the brie melts over the onions…heaven! Pinned this!

  • March 7, 2013 at 1:32 PM

    I absolutely love carmelized onions! They add so much flavor! I made a great carmelized onion dip – I will have to share it on my blog soon! 🙂 Thanks for a reminder!

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