These Slow Cooker Caramelized Onions are a delicious way to add savory flavor to food, without the hands-on time of the stove-top method.
There's nothing quite like caramelized onions to add savory flavor to foods. They're a little sweet, intensely umami, and basically taste nothing like fresh onions.
But there's a catch. Caramelized onions are very time-consuming to make, and if you use the traditional stovetop method, that time is mostly hands-on.
Luckily, I'm here to give my fellow caramelized onion lovers some good news. There's an easier way.
You can use your slow cooker to make delicious caramelized onions - No more standing at your stove and stirring forever!
Unfortunately, this Slow Cooker Caramelized Onions recipe won't actually save you any time, but it will remove the majority of the hands-on aspect from the traditional stove-top method.
That means that while your onions are becoming nice and golden brown all by themselves in the slow cooker, you'll be free to do what ever you want!
Cook the rest of your meal? Bake a cake? Do yoga? Binge your latest TV show? It's totally up to you!
How to make Slow Cooker Caramelized Onions:
Making these sweet and savory flavor bombs is as easy as slicing some onions, mixing with some butter, oil, brown sugar, salt, and pepper in a slow cooker.
While you skip the endless stirring at the stove, you do still want to keep your eye on them and stir occasionally to make sure they're not burning.
Caramelized Onion Ingredients:
- Unsalted butter: you can use dairy free butter alternative to make this recipe dairy free or vegan. Or you can replace with more olive oil.
- Olive oil
- Yellow onions: Look for large ones, which means less trimming and peeling since you'll be using a lot of them.
- Brown sugar
- Kosher salt
- Ground black pepper
- Dried thyme - optional, but adds a little more flavor.
As with most recipes that require any chopping or slicing of vegetables, you'll want to make sure you have a good, sharp knife.
Also, since this recipe is designed specifically to use a slow cooker, you'll want to make sure you have one of those.
I think a small to medium slow cooker will work. I made them successfully in my medium (6.5-quart) slow cooker, but a smaller 4-quart one would work too. Avoid using anything larger than a 7-quart slow cooker, as there would be a greater chance of the onions burning.
It's always helpful to use a slow cooker that has a timer function, in case you're not around to turn it off when it's done, or you lose track of time.
How do you use caramelized onions?
Caramelized onions are a versatile way to add flavor to lots of foods. They can be used in sandwiches, salads, soups, appetizers, dips, and pizza, among other things.
Here are some of my recipes that use caramelized onions:
Slow Cooker Caramelized Onions Nutrition Notes:
The recipe below makes about 3 cups of caramelized onions. The nutrition information in the recipe uses ¼ cup as one serving.
The nutrition information below uses regular unsalted butter for the calculations. Substituting additional olive oil will reduce the saturated fat content of the onions.
Slow Cooker Caramelized Onions
- Slow Cooker
- 2 Tablespoons unsalted butter (use Dairy Free butter alternative or replace with 2 Tablespoons extra olive oil if you need this recipe to be Dairy Free or Vegan)
- 2 Tablespoons olive oil
- 4 pounds yellow onions
- 1 Tablespoon brown sugar
- 2 teaspoons kosher salt
- 1 teaspoon ground black pepper
- ¼ teaspoon dried thyme (optional)
- Turn slow cooker on to high. Add butter and olive oil and cook until butter is melted while you're cutting the onions.
- Trim off the non root end off the onion, then remove all the papery peel. Cut the onion in half through the root end. Trim off the root end from both halves, place the onion flat side down and slice ¼" thick (with the grain).
- Transfer the sliced onions to the slow cooker, and stir in the brown sugar, salt, pepper, and thyme (if using). Cook for 2 hours on high, then reduce to low and cook for an additional 4-6 hours, until onions are very soft and golden brown. Make sure to check your onions often, stirring occasionally. If at any point the onions are burning on the bottom, add a small amount (1-2 Tablespoons) of water. Use caramelized onions immediately, or refrigerate for up to 2 days, or freeze in individual serving sizes for later use.