Slow-Cooker Caramelized Onions


What’s for dinner??

If answering this question causes you daily stress then being prepared with ready-to-go versatile ingredients in your fridge/freezer can be a great asset!

Making caramelized onions takes time and effort that many of us are not willing to put in after a day at work. Until I started making them in my slow-cooker I rarely had them on hand. I am much too impatient for that. Now they have become somewhat of an addiction… they make so many meals so much better, I just can’t go without them anymore!

What have a I been using these deliciously sweet, flavorful morsels on?

  • pizza
  • sandwiches/ burgers
  • wraps/quesadillas
  • grilled cheese and caramelized onion sandwiches
  • nachos
  • soups
  • pasta
  • frittata and other egg dishes
  • dips
  • bruschetta

They pretty much just make EVERYTHING better.

Stirring the onions every 2-3 hours or so can help them cook more evenly but is not required. It would be best to trial this recipe once on a lazy day at home – if successful you can start making them in your sleep! The slow-cooker can cook them to perfection overnight while you get your much needed rest.


Make sure you freeze a few bags when they are done. They are so easy to thaw for impressive week night meals. If there is any leftover liquid use it for soups, cooking grains or for risotto — waste not!

Slow-Cooker Caramelized Onions


  • 5-6 med-lrg yellow onions (this can vary depending on your slow-cooker, you want it to be 1/2 – 3/4 full)
  • 2-3 tablespoons olive oil (using a chili infused olive oil is yummy!)
  • 1/2 tsp salt


  • Half onions and peel them. At this point you can either slice them all thinly with a sharp knife (onion goggles required!) OR you can use the slicer blade on your food processor like me!
  • Put onions in the slow-cooker and mix in the salt and oil.
  • Turn the slow-cooker on low and cook for 8-10 hours. With my slow-cooker I found 8 hours with the lid closed and a 1/2 hour with it open to reduce the liquid was perfect. The longer they cook the more the flavor develops.
  • Refrigerate and/or freeze portions of the onions. Reserve leftover liquid for other purposes (mentioned above).


5 Comments || Slow-Cooker Caramelized Onions

  1. Another great use for my slow cooker! I love onions on everything, so I’ll definitely have to try this.

    • UpBeet,RD

      I love onions on everything too! But they’re just such a pain to make properly. Definitely a perfect job for the slow cooker! Enjoy!!

  2. Holy crap!! This is awesome!! Yep, I’m totally doing this!!

    • UpBeet,RD

      They are SO good! I always have them in the freezer now!! Makes meal prep so much easier too!

Share your thoughts + comments with Melissa (upbeet, RD)!


- Formerly known as Apron Strings and Healthy Things -

© 2014 Upbeet. All rights reserved.