Our easy slow cooker caramelized onions (no oil) recipe can be prepped in 10 minutes. They are the best 3 ingredients side dish for burgers that are sweet and savory with butter and a bit of brown sugar.

Also known as fried onion paste, this Crockpot recipe can be used on or in all sorts of recipes so get ready for the goodness. Browned with natural sweetness released as they soften in the Crockpot all day, your family is going to love this alongside your dinner tonight.

If you want to know How to Cook Beef Heart the best way, it includes these!! If we plan on making a batch we'll plan a meal that night with them as well as something the next day with them too. You can't get enough and you do NOT want to waste even one bite.

Now we have made this a few different ways. When in a hurry we can make a sort of version as Air Fryer Onionsbut it is nothing like a bite of these. The trick is to not rush the deliciousness and take your time for the best results. There isn't any alternative to time for this old fashioned dish.

How long does it take to cook onions in a slow cooker

Ingredient notes

You only need onions salt and butter to make this. We suggest salted Kerrygold for the smoothest and richest flavor. The addition of brown sugar will give you a sweeter note but not necessary. It depends on the flavor profile you are going for really.

What type of onions are best to caramelize?

Sweet onions, like Vidalia, Walla Walla, or Maui, are best for caramelized onions because their natural sugars create a rich, deep flavor and beautiful golden color as they cook. However, yellow onions are a versatile and more affordable option that also caramelize well, making them a popular choice for everyday use.

Can you use oil instead of butter?

If you wanted to make this dairy free you could with oil instead but we will tell you that vegan plant based product from Country Crock is way better. It is way more flavorful but needs a pinch of salt with that.

The whole idea is that strips of onions (with butter and sometimes brown sugar) have been cooked slowly over low to medium heat until their natural sugars break down and turn golden brown. This slow cooking process transforms their natural flavor, texture, and appearance resulting in a sweet, rich, and savory ingredient that adds depth to various dishes.

How Long to Caramelize Onions in Slow Cooker

10 hours on low is about solid to caramelize onions in slow cooker perfectly. This cook time is subjective of course depending on how soft and browned you want them to be. Longer will yield a sweeter and/or more of a onion paste of sorts.

How Long to Caramelize Onions on High

If you want to speed up the process and cook on high for 6-7 hours. We would highly recommend that you stir every other hour or so with this heat level or else the pieces on the bottom and sides will begin to burn the pieces touching that.

Hand lifting lid from slow cooker filled with shredded potatoes and caramelized onions.

Is it better to caramelize onions on high or low?

You do not want to speed up the process!! Leave yourself plenty of time to make these or the texture will not be right and the flavors won't permeate properly to create that deep rich flavor you want.

How to Caramelize Onions Overnight

You could certainly cook these overnight in a safe way low and slow. prepare before you go to bed and they will be ready in the morning to serve with eggs. They are almost better the next day too, softer….

Slow Cooker Caramelized Onions Recipe

By Slow cooker caramelized onions are easy to do with 10 minutes prep work beforehand. Best 3 ingredient side dish for burgers. Make sweeter with brown sugar or keep savory with butter. Prep: 15 minutes minsCook: 10 hours hrsServings: 12 Save Recipe Saved! Pin Recipe Comment Print Recipe

Equipment

Ingredients

8 large onionssliced
1 tsp salt
1/4 cup butter melted

Instructions

Remove skins and slice onions thinly. Add to a slow cooker. Sprinkle onions with salt and drizzle with melted butter. Toss to coat onions. (if you want a touch of sweetness add 1 tbsp of brown sugar into mix too)
Cover and heat on low for 10 hours. If onions have too much liquid, or you want them browner, continue to cook another 2-4 hours on low until liquid is reduced. Remove with slotted spoon from slow cooker and use in your favorite recipes. Makes 2-1/3 to 3 cups of cooked onions

Notes

Slow cooker caramelized onions on high

We always recommend low but if you wanted to speed it up a bit you could first set to high for the first 2 hours. Then reduce the heat to low for 5 hours or until tender to your liking. On high the whole time won't yield you the deep flavor you want and would expect but this option is a good go between for less cook time.

Nutrition

Nutrition information is automatically calculated, so should only be used as an approximation.

Additional Info

Course: Side DishCuisine: American Tried this recipe?Mention @thetypical_mom or tag #thetypicalmom!

How to save leftovers

If you want to save for later you can add to jars but leave lid ajar until completely cooled. Keep in the fridge up to 4-5 days. Include extra liquid in there for flavor. You can freeze in ice cube trays for longer too.

Kitchen questions

What is the best way to make a large batch of caramelized onions?

We think this is it, it makes 2-1/3 to 3 cups of cooked onions when done which is quite a bit compared to how much a skillet will hold. Another plus is for a large group you can switch it to low and they get better and better, able to serve for a longer period of time.

How long do homemade caramelized onions last?

If stored properly (completely cooled first) they will save for a good 4-5 days in the fridge or up to 6 months in the freezer. For short term store in a well sealed glass container (like a mason jar) and to freeze you should spoon into an ice cube tray, pop out when frozen and store in a freezer bag.

What to Make with Caramelized Onions

If you know How to Cook Beef Liver you know how important this part of that dish is. Without them most people won't even touch that as a “meal”. Of course we have shown you how to make this on the stove so it can be served together but the longer your strips of onions cook the better they become so it was time to share this method too.

The negative to it is that you don't get a nice crisp on the outside. If that is important to you we would use a pan on your stove. You can enjoy this with beef (linked above), chicken, deer or even How to Cook Pork Liver with this on top is good our friends.