I once read that you could make a batch of caramelized onions in the Crock Pot and freeze them, but I couldn’t find a recipe. So I decided to experiment and see if I could figure out the process.
It turns out that cooking caramelized onions in a slow cooker is not only super easy, the onions turn out amazingly golden brown, sweet and delicious.

Step by Step Directions
I knew I wanted pieces of onion, not stringy slices, so I peeled and cut 5 yellow onions like this:

Here’s how they looked prior to cooking:

I tossed them with 1/4 cup of melted butter (I’m sure you could also use olive oil instead), a generous sprinkling of salt, several generous grindings of black pepper, and a teaspoon of sugar to jump-start the caramelizing process.
Then I set the Crock Pot temperature on Low. After 4 hours of cooking, they looked like this:

After 8 hours of cooking, they were nicely browned, wonderfully sweet and caramelized. They had reduced down to about two cups:

I divided them into four 1/2 cup portions and froze them in freezer bags. The portions thaw quickly and the onions are absolutely terrific on pizzas and bruschetta. I’ve also added them to homemade spaghetti sauce and soup.
Using the slow cooker is much easier than standing at the stove and cooking and stirring the onions, and I love having caramelized onions ready to go in the freezer. All in all, I would say this experiment was a big success!
About Eliza Cross
Eliza Cross is the author of 17 books, including Small Bites, 101 Things To Do With Bacon, and BERRIES. She enjoys sharing ideas to simplify cooking, gardening, and home projects. She is also the owner of Cross Media, Inc. and founder of the BENSA Bacon Lovers Society.
Thanks for sharing this! My onions go straight from raw to burnt when I cook them on the stove top. I guess I am too impatient :-).
*sigh* I couldn’t cut consistently nice, neat slices like that if my life depended on it.
Ooh! Eliza, I can’t WAIT to try this this weekend! THANK YOU! = )