Slow Cooker Caramelized Onions

Sauté Onions on the stove-top can take time with having to stir the onions to fully caramelize them. With this crockpot method the slow cooker does all the work while being low-maintenance. This is now my favorite Kitchen Hack!

These golden brown onions are perfect to serve in my scrambled eggs in the morning or on my Western Burger for dinner. They are packed with flavor and easy to store!

Why Make Caramelized Onions in the Slow Cooker?

These sweet, savory caramelized onions is the perfect dish to make in your slow cooker to meal prep for the week. We love to make a large batch for later use as a pizza topping or in my omelets.

Cooking in the slow cooker is the perfect set it and forget it hack! The rich, deep color and amazing flavor makes it the perfect kitchen staple without much work.

Ingredients

• Onions – Use white onions or yellow onions. Red Onions can also be used
• Butter – We used unsalted butter

Scroll to the bottom for the full recipe in the recipe card.

How to Make Caramelized Onions in the Slow Cooker

Step 1 – Peel and slice the onions into thin slices. 

Step 2 – Add the onions to a slow cooker.  

Step 3 – Dice the butter into small pieces and layer it on top of the onions. 

Step 4 – Cook on low for 8-10 hours (stirring a few times) until the onions are golden brown and caramelized.  

• Step 5 – Serve immediately while warm or refrigerate in a container for up to 3 days. 

Recipe Tips

• Uniform Slicing – To ensure that your onions are cut about the same size for even cooking, we recommend using a mandoline.
• Deeply Caramelizing – If you perfect that your onions have a deeper color to them, continue cooking them with the lid ajar.
• Save Juice – If all the juice do not cook off, save this flavorful juice in an ice cube tray to use in soups, stews and more.

Flavor Variation Ideas

• Balsamic – Add in 2 Tbsp of balsamic vinegar towards the end of cooking time for a tangy flavor.
• Fresh Herbs – For a delicious variation, add thyme sprigs to the slow cooker while cooking. Remove before serving and storing.
• Savory Flavor – Stir in 1 tsp of miso paste after cooking for a umami kick

Serving Ideas

Making caramelized onions in bulk allows you to use them in many recipes. Try them in these delicious recipes.

• Homemade Spaghetti Sauce Recipe
• Meatloaf Burgers
• Slow Cooker French Onion Soup Recipe
• Hot Honey Pepperoni Pizza
• Baked Mac and Cheese
• Ground Chicken Burgers

Storage and Reheating Tips

• Fridge – Any leftovers can be kept for up to 3 days in the refrigerator. 
• Freezer – Place the leftovers in a freezer safe container for up to 3 months. Thaw in the refrigerator overnight when ready to serve.
• Reheating – Reheat the leftovers in the microwave or saute in a skillet over medium heat to serve over Instant Pot Beef Stew, Shredded Beef Sandwiches or Italian Sausage Pasta.