How to Caramelize Onions





Introduction: How to Caramelize Onions

About: I work at instructables by day, and turn into a stitch witch by night. follow me on instagram @jessyratfink to see what i'm working on! ^_^

Caramelized onions are something I don't make very often because they take forever, but they really are worth it if you've got the time! I like making true caramelized onions - no sugar or vinegar here! Just lovely onion flavor.

You're looking at 45-60 minutes of cook time, so I normally try to multitask and cook other things - that way I'm in the kitchen to keep an eye on the caramelized onions but I'm not bored. :D

(Yesterday I made two cakes and some buttercream while the onions were going - you really do have time to make a lot!)

P.S. There are tons of tricks for cooking caramelized onions more quickly and efficiently, but I've never found them particularly useful. Many of them change the texture of the onions, so be warned! But if you feel like experimenting, check out this awesome write up over at Serious Eats.

Step 1: What You'll Need:

  • several onions - any color you like!
  • olive oil or butter (or both!)
  • salt
  • water
  • a good heavy pan, I prefer stainless or cast iron - non-stick is not ideal.

I prefer to use a mix of yellow and white onions, but you can really use whatever you like!

The reason I say that you shouldn't use non-stick is because you really do want the onions to get a bit stuck to the pan so you get those lovely little brown bits to scrape up. This is similar to the pan I use at home - it's a workhorse! Great all around, but especially for caramelized onions, tomato sauces and pan frying. :)

Step 2: Slice the Onions

I prefer to slice the onions across the grain (from root to tip) instead of with it for caramelized onions - it makes the slices a little fatter so they can better stand the heat. :)

But you can also do this part however you like - just make sure they're fairly similar in size and not too skinny!

Step 3: Heat Up Your Skillet and Add Your Fats

I like to do half and half olive oil and butter. For five onions, I'm using about 2 tablespoons of oil and 2 tablespoons of unsalted butter.

Place the skillet over medium heat and melt the fats together.

Step 4: Add in the Onions + a Few Pinches of Salt

Add the onions in and toss them around so every onion is coated in fat. If they don't look glossy, you'll need to add a little more fat. If the onions are dry, they will be more likely to burn and stick to the pan.

Once that's done, you can add the salt!

Salt is my secret for great caramelized onions. I do 2-3 pinches for this amount of onions - maybe around a teaspoon?

The salt causes the onions to release moisture, which means that liquid will evaporate in the pan leaving you with open access to the sugars in the onions. Yay caramelization! Plus, salty caramelized onions are delicious since they get so sweet on their own. :D

Step 5: Cooking the Onions, the First Half

There are two major things to remember when cooking caramelized onions:

  1. Stir and scrape the bottom often - every few minutes.
  2. Don't crank the heat over medium, as that is how you'll end up burning the onions instead of caramelizing.

For the first 20-30 minutes, the onions should continue to release quite a bit of liquid - keep the heat around medium and stir often - every few minutes. Scrape the pan clean every time - if you leave the stuck on sugars in place, they'll burn.

Near the end of this time, the onions will begin to dry out a bit and you'll need to keep a close eye on them. They'll also start to get a little golden brown. :D

Step 6: Cooking the Onions, the Second Half

After 30 minutes, you should definitely see color beginning to form on the onions.

I like to turn the heat down a little at this point and keep a closer eye on them. You'll probably need to stir and scrape them more often as well.

If you go to stir and they're sticking pretty bad, you can add a tiny splash of water. You'll need to either turn the heat down or stir more often to remedy this - you'll figure it out as you go!

I like to stir and then gently push the onions down into a flat even layer, but it's not necessary.

In another 15-30 minutes, the onions should be beautiful and caramelized. Keep them going as long as you want - I like mine to be mostly deep golden brown with a few lighter onions. :)

If you're running into issues, head to the next step to find fixes for the two major things that can go wrong!

Step 7: What to Do If Things Go Terribly Wrong

(Pictured above - scraping off the scary accidental burnination)

Caramelized onions are not the easiest thing to cook because they do require constant babysitting and awareness about what's going on in the pan. But you can fix nearly everything that goes wrong unless you just burn them to a crisp. ;)

My onions have burned to the bottom of the pan - OH GOD WHAT NOW?

If you go to stir the onions and they're sticking badly and the bottom of the pan is a dark brown or black, you've got your heat too high or you're not stirring often enough. But you can fix it!

Turn the heat off (or very low) and push the onions to the sides of the pan. Scrape up the dark burned sugars in the middle with a wooden spoon. Throw this bit away! Then add a couple tablespoons of water, turn the heat back up and stir it around.

If you see any onions that have gone black, chuck those as well - anything black will make the caramelized onions bitter.

My onions are limp and colorless and it's been forever.

You probably don't have your heat high enough - if you're seeing a lot of steam and liquid in the pan, turn up theheat to medium or slightly above. Stir frequently for a few minutes until the steam and liquid dissipates. Then turn the heat back down and continue as normal.

I would not add any more salt at this point without tasting, though.

You may also need to add more fat or oil if the onions aren't getting any color after a few minutes.



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    24 Discussions


    2 years ago

    This worked for me. 24 brown onions, chopped roughly, 2 bulbs of garlic, peeled and crushed, couple tablespoon each oregano, thyme and basil, a good dollop macadamia oil, put into a good sized crock-pot, thoroughly mixed, switched to high, left for 12 hours. Stirred every couple of hours. Near the end, couple of tablespoons rich dark sugar, good pinch of salt. When warm, I put into jars and refrigerated. Good to just snack on, or mix with scrambled egg, on top toasted cheese sandwich, on barbecued sausages.

    From dear, sweet beautiful Adelaide, our Athens of the South.

    1 reply

    We do this frequently. Onions are such a super food to sneak into anything (and everything). I also add Bell Peppers to the saute and/or fresh jalapenos for a mexican flavor kicker.

    Personally I don't throw away the burnt bits I have a container of flotsam and jetsam of cooking and it all goes in for a later, "Fridge Soup". I also like burnt bits as long as it's bits not lots. that's just my taste buds.

    Stir, salt, low and slow. I've been cooking for 40 years, both professionally and at home, and have never found another method that works as well as the original. At the end of the process I do add a small amount of white sugar and continue stirring until that carmelizes as well. I have found that this rounds out the flavor nicely.

    We put the onions in a large flat pan, place the pan in the oven at 350degF and turn the onions over about every 30 minutes. The constant temperature of the oven avoids burning the onions. The process takes about 3 hours.

    I use the lazy mans method of making these, i typically chop the top/bottom off an onion, quarter to eighth it. Toss that into some foil, add a little bit of olive oil and then twist the top.

    Then that thing goes into the grill.

    usually they caamelize pretty well and go good with fajita and gucamole

    1 reply

    That sounds amazing. I cannot wait to get a grill. :D

    My latest trick for adding a little sugar is a few drops of good maple syrup. It adds some sweet with a bit of richness that you can't put your finger on. Careful too much will show it's maple flavor.

    I use it in allot of my cooking. Even steaks. Great onion recipe !

    If you're not in a hurry, you can put onions in a slow cooker with a little olive oil and let them sit overnight on low heat. In the morning, you get perfectly caramelized onions. And sticking isn't a worry, since you're on such low heat and the insides of most crocks are non-stick.

    I do this with my French Onion Soup recipe made in a crockpot. Six medium-sized sweet onions and about three tablespoons of olive oil go in the cooker at bedtime along with any seasonings (and I use a few sprigs of fresh thyme to get things started). In the morning, they're perfect and ready for the addition of all the other stuff that makes up the soup.

    2 replies

    I actually tried that and it completely failed for me. Cooked them for 16 hours (they just never stopped releasing water - it was wild and I was perplexed!) and was left with a terrible tasting and oddly textured mess. I think it may have to do with me living so high up in altitude! I was going to enter it into the Fail Contest we had here, but ran out of time.

    I'm happy it works for you though! It seems so convenient. :)

    Sorry to hear it didn't work for you. I was quite skeptical when I tried it, since for about the first eight hours the onions just sort of sat there, and when I went out for my 5:30am morning run, they were still white. But when I got back in after running for about an hour and a half, they were perfect.

    Then again, I'm at 714 feet above mean sea level. I know this because I'm currently designing parts for my reproduction WWI biplane, and one of the parts I'm making is an altimeter. Look for an instructable on that whenever I get done doing projects and start actually writing them up.

    The biplane, by the way, has two seats, and I'm willing to trade some open cockpit fun for home-baked cookies as long as you don't tell the FAA I took compensation for a ride. (Attached is photo of the tube frame with QC inspector at work.) Just make sure that if you're where the air is thin, there's a long runway somewhere. There's a reason that Denver-Stapleton has some of the longest runways in the world. And where flying is concerned, I'd rather not enter any FAIL contests myself.

    Keep calm, and cook on!

    Fuse & Gear, 9-13-12_small.jpg

    2 years ago

    I found out a little secret to make tasty caramelised onions from a guy running a hot dog stand (charity). He poured some coca cola over them and boiled off the water leaving sugar and flavours in the onions in the fry pan or griddle. I was surprised to hear that and when I tried it myself it worked. :-)

    1 reply

    Ohhhhhh that sounds interesting. I love using Coke to cook with! I bet those would be great with barbeque :D

    I MP

    2 years ago

    Take your caramelized onions and spread them into the bottoms of fillo cups, add a slice of brie on top and place under the broiler until the cheese melts. Place on platter, place on table and get out tof the way to ensure you are not run over and trampled by the ravenous horde.

    A pinch is just that, a teaspoon is not a few pinches unless you are the jolly green giant.

    Use salted butter and don't add any if you want salt.

    Near the end add some rendered bacon fat with the bacon brown bits. OOO, AAAHH Special so very special. Kinda gilding the Lilly, but hey , bacon rules, margerine drools...uh yea..

    But in all fairness just the way you made them I WANT THEM ON MY BURGER, or over a medium, STEAK Grilled nicely!!!

    You have done well ObiWan in your passing of the sacred knowlege.


    2 years ago

    Oh for heavens sake, if you cook the onions in too much water just pour it off and save it for gravy or soup. A little too over cooked and mushy. Drain well and spread on toast or sandwiches. Too salty? add them to mashed potatoes. Use in place of tomato sauce when you make your own pizza.

    It's a thin line between caramelized onion and burned onion. That's what I learned from practice xD

    I sometimes put a dash of brown sugar inside... seems like cheating it a little bit, but it sure as hell does a good job!