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Everything you need to know about making perfect caramelized onions, from cutting, peeling and cooking is right here in our caramelized onion recipe and post.
Perfect caramelized onions are easy to make when you follow a few simple rules.
The first thing you need to know is that there is a huge difference between caramelized onions, fried onions, and sautéed onions.
Sautéed onions are what you find on Philly Cheesesteaks and sometimes they are served with fajitas. These are more like sauteed onions.
Sauteed onions will not be anywhere near as sweet and will have more onion flavor than a caramelized onion.
If you want super dark kind of crispy onions, caramelizing is not the route you are looking for either. You are looking for fried onions.
Fried onions are generally sliced super thin and deep-fried. I am not talking about onion rings that are battered and deep-fried. I am talking about sticking raw onions directly into the oil.
Low heat and slow cooking is the only way you are ever going to achieve deep brown sweet and savory caramelized onions. There no shortcuts.
If you are caramelizing onions correctly, low and slow, there is no need for adding sugar. There is more than enough sugar in onions if you take the time to coax them out.
Choosing Onions for Caramelizing
White onions, yellow onions, red onions, Spanish onions, and Vidalia onions are all great choices for caramelized onions.
I would caution you on the use of red onions. If you are going to use your caramelized onions in French Onion soup, they might make your broth a weird color.
I do not waste money buying Vidalia or sweet onions for caramelizing. Plain yellow and white onions will provide enough sweetness.
How Many Onions
The amount of onions you will need to start with is going to be influenced by the amount of onions you want at the end.
I would recommend that you start with at least 2 to 3 large onions so that none of the onions spend too much time on the bottom of the pan during the beginning stages of cooking.
2 extra large onions will give you about 8 to 10 cups of sliced raw onions.
8 cups of sliced onions with 2 tablespoons of oil will produce around 1 cup of caramelized onions.
How to Peel an Onion
I find the easiest method for peeling an onion is to cut it in half from the top to the root end, lay it cut side down and then cut off the top and bottom.
Now you can get ahold of the skin.
Remove the outer skin. You also need to remove the super thin onion layer that is right under the skin. Large onions tend to have that papery layer.
If you have ever eaten an onion ring and the onion was just too tough to eat, it is because someone did not remove that thin layer.
That thin layer is actually trying to turn into a paper skin.
If I am peeling an onion for something that needs rings, like onion rings or placing on burgers, I cut off the top and root end. Then I use my knife to cut through the skin and at least one layer of the onion. Then I get my fingers into that cut and pull the cut layers off.
How to Slice an Onion for Caramelized Onions
Make sure you are in a well-ventilated area. Slicing a lot of onions in one spot is going to produce a whole lot of sulfur compounds. There will be tears.
Using a peeled onion, cut the onion in half and lay on cut side down onto a cutting board.
Start slicing the onion from a side, you do not want to slice these into half-moons or rings, these will be too long and appear stringy after cooking.
You are looking for thin slivers of onion pieces. I cut my onions into 1/4-inch slivers.
How to Cook Caramelized Onions
Caramelized onions need to be cooked low and slow a lot like smoked meats.
Slow cooking gives the onions times to break down the sugars without burning them.
We don’t cook our caramelized onions on high for the same reason we don’t cook our homemade caramels on high. Burnt sugar can be bitter and nasty.
My preferred method for caramelizing onions is to use an electric skillet.
Electric Skillet Method – My Favorite Way to Make Caramelized Onions
Set an electric skillet to 200 ⁰F and add the oil and allow the oil to heat up. Side note: if you are going to use your caramelized onions for French onion soup, add a couple of tablespoons of butter.
Once the oil is hot, add the onions, put the lid on the skillet and walk away for 20 minutes. I know, the struggle is real, but walk away.
After 20 minutes stir and walk away again for another 20 minutes.
After 40 minutes, some of the onions should begin to lightly brown.
Now crack the lid to allow the steam to start escaping and stir every 10 minutes. As the liquid begins to evaporate, increase stirring to prevent burning.
Always remember to scrap the bottom of the pan to keep all that sugar from sticking to the bottom and burning. All that goodness down there will add a nice dark color to your onions too!
I have Alexa set a timer for me, otherwise, I am likely to walk away and forget they are cooking. You really need to stir caramelized onions regularly to keep them all cooking evenly.
Some electric skillets run hotter than others, so you may need to adjust your temperature up just a tad to keep the onions at a very slow simmer.
Depending on how many onions you have in the skillet, the time to produce perfect caramelized onions will take between 1 1/2 to 2 1/2 hours.
Just remember to keep moving the onions around to encourage even browning.
Onions can be caramelized on a stovetop, but you want to make sure that the heat is never any higher than medium-low. Use the same method as using an electric skillet, but decrease the time for checking and stirring the onions by half.
This method will take less time but will need to be watched much closer. There really is a fine line between perfectly caramelized onions and overcooked onions.
Slow Cooker Method
Mix the onions well with oil before turning on the slow cooker.
Set the slow cooker to high and stir every hour for the first 4 hours, then every half an hour until they are done. This will take 6 to 8 hours depending on how quickly your crockpot heats up.
Alternatively, you can set the slow cooker to low and stir every 2 to 3 hours. It will take around 11 hours at low.
I do not like the slow cooker method because the sides of a slow cooker tend to get hot and any onions that are touching the sides tend to burn.
The onions come out more like steamed onions in my opinion.
I also think it is hard enough waiting 40 minutes or more for caramelized onions and no one should have to wait half of a day to get their hands on some!
But to each their own!
What Color Will Caramelized Onions be when done
If you have used the electric skillet or stovetop method, your onions should be dark brown.
When using the slow cooker your onions may never get past a pale brown color before you lose your patience.
The darker the color. The sweeter the onions will be. Just don’t go so far as to black-brown or the caramelized onions will taste burnt.
Tips for Success
- Low and Slow
- Do not add salt
- Do not add sugar
- Follow the suggested times for stirring
- Stir often near the end
- Do not walk away to do something else near the end, no need burning the onions you jus spent 2 hours preparing!
Where to Use Caramelized onions
- French Onion Soup – our favorite use for caramelized onions
- Pizza Topping
- Hot Dogs
- Flatbread Topping
Caramelized Onions in Bacon Jam
Bacon jam has caramelized onions too, but these onions are sweated in bacon grease and then allowed to caramelize slowly with cooked bacon. While you might be able to add some caramelized onions to your bacon jam, the best flavors will happen when you allow the onions to caramelize with the bacon.
More Recipes Featuring Onions from Pear Tree Kitchen:
- Electric Skillet
- 1 tablespoon olive oil
- 8 cups thinly sliced onions about 2 large onions
- Heat olive oil in electric skillet set to 200 Degrees f.
- Add onions and cover, cook for 20 minutes.
- Stir, Cook for an additional 20 minutes covered.
- Stir, remove cover and cook another 20 minutes.
- As onions begin to brown stir every 5 to 10 minutes until all the onions are golden brown. This may take up to another 90 minutes.
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