Wednesday, May 20th, 2009...11:15 pm

How to Caramelize Onions

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A week or two back, someone on Metafilter asked what people’s power ingredients were–what do you add to your cooking that makes it amazing?

My answer, obviously, was caramelized onions, which I will eat on pretty much anything, including a spoon. I also explained how to caramelize onions, since it’s a sad fact of life that for some reason, most people view “caramelizing” as something that takes about five minutes in a hot pan. This is clearly wrong, so now, I explain to you how to caramelize onions.

First, assemble your workspace.


Bag of onions, really sharp knife, mandoline, ginger ale, and, obviously, the motivational cookie. (You guys don’t have motivational cookies when you’re cooking? You’re missing out. [Also, that cookie was delicious.]) The mandoline is actually optional, though it does make things a lot easier. Without one, I find that the slicing part of this takes me several hours, since I have to leave the kitchen in tears a fair bit.

Also, it’s worth mentioning here that the bag you see there is a ten-pound bag of onions. I would suggest not doing ten pounds of onions at a time, as I discovered that it both takes forever and also causes everyone in the house to spend a good hour with their eyes watering. That said, a three-pound bag works just fine.

Slicing time.


See that? I’m demonstrating what not to do. Don’t be like me. Use the holder for your mandoline. (I couldn’t find mine, which was unwise, as historically when I don’t use it, I lose parts of my finger. Shockingly, I escaped unscathed this time.)

Slice your onions as thin as you can. I believe that the mandoline was on a 1/8″ setting, which seemed to work pretty well.

This is what ten pounds of sliced onions in a gallon-sized bucket looks like.


Time for cooking.


In a pot–I used the Club Cookware of my husband’s dead grandmother, and incidentally, should anyone know how to remove the orangish stains that seem impervious to even steel wool, let me know, would you? …let me start over. In a pot, heat up equal parts butter and olive oil. (If you’re vegan, go ahead and use all olive oil. I don’t think that anyone will really notice.) Use about a tablespoon of fat per pound to pound and a half of onion.


Dump your sliced onions into the pot. Sprinkle them with a tablespoon of kosher salt, leave them on medium-low heat–my stove has eight levels of heat, and I left the knob between two and three. Stir them up a bit, and then walk away.

It you’re doing three pounds of onions, you’ll want to come back in about ten or fifteen minutes and stir them up.


This was probably forty-five minutes later, because I am a crazy person who tries to cook ten pounds of onions at a time. Anyhow, stir them up, and then resign yourself to stirring them again every ten to fifteen minutes.


I think that this was at nearly the two-hour point for me. If you are sane, it’s probably more like forty-five minutes. Keep stirring them every once in a while. In the entirely likely event that you forgot to stir and things got a tiny bit blackened, throw in about a quarter cup of water and stir them really well–there’s some sort of magical alchemy that happens and it unburns them.


After two and a half hours or so–or, you know, an hour to an hour and fifteen minutes, if you’re not me–you will have a fraction of the onions that you started out with, and they’ll be a deep brown. (Somewhat less red than the picture above, but the lighting in my kitchen was weird.) What you’re left with isn’t going to resemble onions at all, but sort of a thick, slightly stringy, absolutely delicious onion goop.

So now you have all this onion goop, and there’s way more of it than you’re ever going to manage to eat before they go off. Let it cool for a few hours (or toss it in the fridge overnight) and then make an onion log for freezing.


Lay out a sheet of cling film, and put a line of onions down the middle of it. Just make a long pile, basically. (I tried to take pictures of it, but–well, but caramelized onions are hard to take pictures of when there’s no light.) Fold the cling film like you’re folding a burrito: bring up one end over the onions, fold the sides over, and then fold up the far end. Wrap this in tinfoil and stick it in the freezer.

Assuming that you’re using an average freezer and not a deep freeze, the onions will freeze, but remain soft enough that you can cut off a disk with a sharp knife. You can either throw it directly into whatever you’re cooking (pasta sauce, risotto, curry, lentils…) or thaw it and use it as a condiment. It makes sandwiches more delicious and is amazing on bread with some brie. It’s sort of a big time investment, but it makes enough that you can do it one some lazy Saturday and then just magically have delicious food for the next month–my kind of cooking.


  • This is delicious! And I think you should start marketing motivational cookies ;-)

  • So the ginger al is like the cookie – it doesn’t go in the recipe? Somehow I expected it to. This looks so good, I am super tempted! But I don’t have a mandoline, wah.

  • Yeah, the ginger ale goes in my belly–I should’ve made note of that!

    I think that it’s doable without a mandoline, especially if you’re only making a small amount–I figure that a two pounds of onions is probably about five or six of them, and slicing five or six onions isn’t that bad, I don’t think. You should try!

  • anatsuno: A mandoline isn’t necessary, but it makes the chopping a lot faster and the evenly-cut slices cook at the same rate so you get a more consistent result. For me, the texture of the caramelized onions is a little better when thinly sliced. But even if they are cut roughly and unevenly they will still taste great when cooked this way but they will require more attention stirring the pot in the first 30-45 minutes when you’re sweating the water out of the onions.

    Meghan: Very nice and thanks. Try a splash of white wine towards the end, super delicious.

  • [...] sliced up throughout. This was really fun and oh my goodness the onions are delectable. I used this [...]

  • Thanks for writing this! I used the onions as part of an array of cracker toppings – people loved them the most. Plus, it’s so inexpensive. I’ll definitely do a bigger batch next time.

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