Juicy sweet slow cooker caramelized onions require no hovering over the stove, make your house smell divine, and are freezer friendly!
Y’all. I’ve been making these juicy sweet caramelized onions in the slow cooker for YEARS now. I remember originally researching how to make caramelized onions and stumbling upon this method. After reviewing many painstaking how-to tutorials on caramelized onions, I decided upon the slow cooker method and never looked back.
I use them most frequently in my animal-style meatloaf, but Mr. Hungry demolishes them on everything from burgers to Chinese food. He’s so obsessed I have to quickly use what I need and freeze at least one cup before he plows through it. Luckily the recipe I’m about to give you makes four cups, so you should have plenty even if someone in your house wants to use them on EVERYTHING.
How To Make Slow Cooker Carmelized Onions
Chop onions. Add butter and salt. Walk away from the slow cooker, which is on low for 8-12 hours. But, really. That’s it.
Okay, back up, what now? Let’s talk specifics.
What kind of onions do you use in slow cooker caramelized onions?
I always use sweet yellow onions because I want the mild yet depth of flavor they provide. But, in theory, you could use any onion you wanted, even red onions, but the flavor will be different.
How many onions can use in slow cooker caramelized onions?
I typically use five small organic onions. If you can fit more in your slow cooker, then go ahead and do it. You will also need to increase the butter and salt slightly. I recently used five big onions instead of small, and I didn’t get the depth of color I wanted, likely because I did not increase the butter and salt enough.
Butter or oil?
You can use either melted butter or oil. But I prefer butter every time. Buttery caramelized onions have a richness that those made with oil do not. If you have dairy intolerance but can tolerate melted ghee, I recommend that as a runner-up. If you can’t use butter or ghee, then use oil. The onions will still caramelize. I would suggest avocado or olive oil.
Is the salt needed for slow cooker caramelized onions?
Yes! It helps draw the water out and dissolve the sugars in the onions. It cooks them down and deepens the flavor and browning of the onions.
Is the sugar needed for slow cooker caramelized onions?
No! Onions contain natural sugars that are used for the caramelization process, so no sugar is needed for slow cooker caramelized onions.
How to Store and Freeze Slow Cooker Caramelized Onions
Store: Store in an airtight container for up to three days in the fridge.
Freeze: Store in a freezer-safe container for up to 3 months.
Slow Cooker Caramelized Onions
- 5 small sweet or yellow onions
- 3 tbsp melted butter or oil
- 1/2 tsp sea salt
- Cut the bottom of each onion, remove the papery outside layer, and then slice the onion into 1/4-inch strips. Discard the root top of the onion.5 small sweet or yellow onions
- Toss sliced onions with melted butter and salt in a slow cooker.5 small sweet or yellow onions, 3 tbsp melted butter, 1/2 tsp sea salt
- Place the lid on and cook for 8-12 hours on low. Stirring the onions about halfway through. If lots of liquid accumulates, you can leave the lid ajar to let the steam out for the last two hours of cooking.
- Onions are done when the desired depth of color and flavor has been reached.