Fool-Proof, Slow Cooker Caramelized Onions


I can eat caramelized onions on and in just about anything. Sandwiches. Salad. Stew. Pizza. On toasted bread. A spoon (Yes. All by themselves and you will not judge me). They’re just that good. They’re such a simple ingredient that can really bump up a dish in a way that other condiments just can’t.

The thing about making caramelized onions is that the process can be both long and tricky. You have to have the time and patience to let the onions cook VERRRRRY low and slow over the stove top in the skillet. You also have to know when and how not to let them cook TOO much so that they scorch and burn.


I won’t lie, they can be a labor of love that fortunately turns out to be well worth it. But to be sure…it can be a labor and for those that are uncomfortable in the kitchen, making caramelized onions just may not seem worth all the effort.

Until now, that is.

All of us caramelized onion lovers–both those who love to cook and those who don’t–listen up. I’m sharing a recipe today that is about to make all of our lives more easier.


I decided to see if I could bypass all that extra-ness with hovering over a skillet of onions waiting on them to caramelize,and see if the slow cooker could do the job just as well. I was totally right. It totally could. And now I’m just left kinda wondering how and why I haven’t done this a loooong time ago.

Alright so, look. You can’t mess this recipe up, guys. Seriously. I don’t care how much of a bad/challenged/struggling cook you think you are, look me in my eyes: (ok, so you can’t do that actually , but pay attention closely.)



This is the like The Elves and the Shoemaker fairy tale that we’ve all been waiting for. Literally, all you have to do is leave your ingredients out overnight in the slow cooker (the elves in this case), let it do its magic, then wake up in the morning and behold the wonder that it’s left for you to partake in. You sprinkle in some sugar, wait a little bit more and BAM. You’re done.

That’s….it. I’m not kidding. I almost couldn’t believe it myself. But the onions were there, finished. And soooo delicious.

A few notes: my #1 onion onion of choice will always be the sweet Vidalia. However, I do enjoy red onions too and when caramelized they take on their own sharp sweetness that goes great with pizza and sandwiches. White onions…meh. I’m not a fan of their peppery bite, but if that’s what floats your boat, have at it Charlie. I’ve also included an option in the recipe for those that prefer a more vinegary acidic flavor to their onions rather than sweetness. Either way, you’re going to be happy with these results. I guarantee it.

Happy Fiesta Friday #144, co-hosted this week by Margy @ La Petite Casserole and Suzanne @ apuginthekitchen.

Foolproof Slow Cooker Caramelized Onions

Recipe by Jess@CookingIsMySport



  • 4-5 large sweet yellow onions, thinly sliced
  • About 1/4 cup vegetable or canola oil
  • Salt and pepper
  • 1-2 tablespoons of light brown sugar OR white wine, or balsamic vinegar (This really just depends on whether you want your onions sweet or acidic. It’s up to you.)



Spray the bottom of a 4-5 quart slow cooker with cooking spray.

Spread the onions into the slow cooker. Drizzle in the vegetable oil in between them as you layer them.

Sprinkle with an even layer of salt and pepper.

Stir together to make sure they’re all evenly coated.

Cover and cook on LOW for 10-12 hours. Towards the 8 or 10th hour, remove the lid and stir the onions. Sprinkle the brown sugar (or wine, or vinegar) evenly over them and re-cover, leaving the lid slightly cracked. Let cook for 1-2 more hours, until they’ve reached the dark color/caramelization you prefer.

Serve on sandwiches, salads, soups, etc.

33 thoughts on “Fool-Proof, Slow Cooker Caramelized Onions

  1. I LOVE onions! LOVE! I have always said that if there was a room air freshener that smelled of fried onions then I would buy loads of them. I rarely make caramelized onions because it can be time intensive so slow cooking them sounds fab. I need to give this a try.

    1. They’re the best aren’t they? I really can’t recommend this recipe enough to fellow caramelized onion lovers; you get a huge batch of them with minimal effort and maximum taste. Thank you Laura!

  2. YES to this!! I love caramelized onions but sometimes they just take so long! It’d be awesome to have dinner have a head start with this slow cooker recipe.

  3. What a brilliant idea for caramelized onions in a slow cooker? Brilliant. What’s not to love for this great short cut. Thank you Jess.

  4. What a great idea! Caramelizing onions in the slow cooker. I tend to get impatient and end ups burning them on the stovetop. This would be a fantastic compliment to any meal.

    1. I’ve messed up a couple batches myself Lily–but fortunately for impatient people like me, this recipe makes it impossible to ever burn onions again lol Thank you!

  5. This is awesome Jess! I never would have even thought to make caramelized onions in a crock pot. I bet they smell delicious while cooking. Using my crock pot is one of my favorite ways to cook in the fall and winter.

  6. I’m with you Jess, just about everything tastes better with a big heaping helping of caramelized onions. This is brilliant. Thank you so much for bringting this to the party.

  7. That’s such a good idea! I love using my slow cooker to make life easier in the kitchen.

    Also, love, love, love the name of your blog. so cute!

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