Easy Crock Pot French Onion Soup + Video
This post may contain affiliate links. Please read my disclosure policy.
Crock Pot French Onion Soup tastes just like your favorite bistro version — but with an easy hands-off method! Be sure to start early in the morning (or the night before) to allow plenty of time for the onions to cook down. This easy crock pot French onion soup may seem humble, but it’s quite impressive in presentation and flavor!
Table of Contents
Crock Pot French Onion Soup
This slow cooker French onion soup recipe is ridiculously easy to put together. Not only is it rich and flavorful, but you can top it with as much cheese as you want!
However, it does take quite a bit of time to make — so be sure to start early in the morning or even the night before.
If you love the rich flavors in this recipe for French onion soup in the crock pot, try combining them with gooey baked mac and cheese!
Or, make a creamy tomato basil alternative that cooks on the stove in just 30 minutes. For something heartier, my crock pot taco soup is sure to hit the spot.
Recipe Video
To see us make this recipe for French onion soup in the crock pot from start to finish, watch the video in this post!
Ingredient Notes and Substitutions
- Onions – While the sweet ones (Vidalia) are preferred, you can get away with any white onion when making this easy crock pot French onion soup.
- Sugar – I prefer brown sugar since it adds to the caramel flavor. Start with a smaller amount and add more to taste if you prefer the dish to be sweeter.
- Flavoring – Adding the sherry and Worcestershire sauce to the vegetables creates a deeper flavor, but you can stir them in with the beef stock instead.
Also, the thyme and bay leaves can be omitted if you don’t have any on hand. - Baguette – A French baguette is my top choice, but sourdough is yummy too.
In a pinch, you could use leftover bread cubes or croutons. And for extra flavor, rub a clove of garlic over the slices before toasting! - Cheese – Shred this yourself, since bagged shreds don’t melt as smoothly. Asiago is a great substitute for Gruyere, or use a blend of both.
Tips and Tricks to Make Perfect Crock Pot French Onion Soup
- Slice the onions thinly and evenly.
Yes, this helps them to cook more evenly — but you also don’t want a thick hunk of onion when you’re eating this soup either!
If your knife skills aren’t great, a mandoline slicer is really helpful. Otherwise, take your time and pay attention to the thickness of each slice as you go.
- Don’t forget the bread and cheese.
Just before your crock pot French onion soup is ready, preheat your broiler and slice up the baguette.
Broil the bread slices for a minute or two on each side, just until toasted, while you divide the soup into bowls.
Place a slice or two of bread on top of each bowl, cover with shredded cheese, and return to the broiler until browned and bubbly on top!
But if you need a gluten-free option, simply skip the bread and just broil the crock pot onion soup with cheese on top.
- Want to reduce the cooking time?
Caramelize your onions on the stove instead! Place them over low heat for about 1 ½ to 2 hours and add a little extra liquid as needed.
Once they are tender and caramelized, transfer them to the crock pot along with any juice from the pan.
Prep Ahead
- Slice onions
- Caramelize them in the crockpot
- Shred cheese
Kitchen Tools You Will Need
- Slow Cooker – Great for soups, roasts, shredded chicken, and more! I love it in the cooler months, but it’s also great in the summer when you don’t want to heat up the whole house with the oven.
- Cheese Grater – Fresh cheese makes this recipe even better! Skip the bagged shreds and buy a block to grate yourself.
- Bread Knife – The serrated blade slices cleanly through baguettes and other loaves.
- Oven-proof Bowls – Stoneware soup crocks are best — and provide that full bistro experience! Make sure they’re safe for broiling, which reaches up to 550°F.
- Baking Sheet – Makes it easier to get your bowls of crock pot onion soup in and out of the oven. You’ll need it to toast the baguette slices too.
Serving Suggestions
Pair crock pot French onion soup with a fresh salad, or serve it as a side with your favorite sandwich.
I think it would be especially delicious with a Gruyere grilled cheese, but a French dip sandwich goes well too.
You could also roast broccoli, zucchini, or butternut squash to make an extra cozy meal. But since this dish is quite savory and filling, it really doesn’t need much else!
Slow Cooker French Onion Soup Recipe FAQ
No, because it’s traditionally made with beef stock. My recipe for French onion soup in the crock pot also includes Worcestershire sauce, which contains anchovies.
However, you can easily make a vegetarian version with a few easy swaps! Replace the beef stock with vegetable stock or mushroom broth, then substitute soy sauce for Worcestershire (or leave it out entirely).
The flavors won’t be as deep, but it’ll still be delicious!
Usually, you can toss them in raw and let them cook with the rest of the ingredients, but they won’t get that delicious caramelized flavor.
Starting them on the stove takes longer up front, or you can prepare them by themselves in the crockpot first. It just depends on how much time you have and how many dishes you want to wash!
Crockpots actually cook food at a consistent heat. The High and Low settings just determine how quickly it reaches that temperature.
So, directions that list a certain amount of time on Low can typically be reduced by half when using High instead.
Although most dishes can be prepared on either setting, certain things like roasts and stews do better with a longer time on Low. The flavors become more developed, and the meat comes out more tender.
Storing and Reheating Crock Pot Onion Soup
Transfer cooled soup to an airtight container and refrigerate for 3-4 days. Wait to add the bread and cheese until after it’s been reheated.
You can also freeze crock pot French onion soup (without the bread and cheese) for up to 3 months.
Thaw in the refrigerator overnight, then reheat on the stove before finishing with the broiling step.
Enjoy!
With love, from our simple kitchen to yours.
Don’t miss a thing! Follow us on
Facebook | Twitter | Pinterest | Instagram
Easy Crock Pot French Onion Soup + Video
Ingredients
- 3 pounds sweet onions, thinly sliced
- 4 tablespoons unsalted butter, melted
- 2 teaspoons brown sugar
- 2 teaspoons sherry vinegar
- 1 tablespoon Worcestershire sauce
- 5 fresh thyme sprigs
- 3 bay leaves
- 6 cups beef stock
- Kosher salt and freshly ground black pepper, to taste
- 12 ounce French baguette, sliced
- 2 cups Gruyère cheese, shredded
Instructions
- Add the thinly sliced onions to a 6-qt slow cooker. Stir in butter, brown sugar, 1 teaspoon salt, sherry vinegar and Worcestershire sauce.
- Cover and cook on high heat for 8-9 hours or on low for about 12-14; or until onions are caramelized and browned. Make sure to stir halfway, as needed, to prevent burning.
- Stir in beef stock, season with salt and pepper, to taste and add thyme sprigs and bay leaves. Cover and cook on high heat for 2-3 hours or on low for 4-5 hours. When ready discard thyme and bay leaves.
- Preheat oven to broil.
- Place baguette slices onto a baking sheet and broil until golden brown on both sides, about 1-2 minutes per side.
- Divide soup into ovenproof bowls, place the bowls on a baking sheet. Top with toasted baguette slices, about two slices per bowl, the bread should cover the soup; top with lots of shredded cheese.
- Place into the oven and broil until the cheese is bubbly and golden brown, about 2 minutes.
- Serve immediately.
Video
Nutrition
All nutritional information is based on third party calculations and is only an estimate. Each recipe’s nutritional value will vary depending on the ingredients used, measuring methods, and portion sizes.
Originally published January 2018, updated and republished August 2024
Disclosure: Posts may contain affiliate links. If you purchase a product through an affiliate link your price will remain the same and The Slow Roasted Italian will automatically receive a small commission. Thank you for supporting us, it helps us keep creating new recipes.
Welcome!
We’re Donna and Chad, the dream team behind The Slow Roasted Italian. Our focus is on taking complicated OUT of the kitchen. Life is busy enough, making meals should be fast and easy, to help make your life as simple as possible. Read More >>
Cannot get to "print" for the onion soup. Every time I click the 'print' option, it goes to a different soup (potato). Very confused.
Thanks Patte, it is fixed now, Enjoy!
I looked for that print button on the recipe and didn't find it, so I highlighted just the title to the end of instructions, right clicked on the highlighted text and clicked print. and it printed picture and all.
Hi! I can't find Sherry Vinegar near me can you sub sherry wine? or can you think of something else that would work? Thanks!
We used sherry wine today and loved the soup.
Thank you! Trying it tomorrow. Everyone is looking forward to it!
I'm in the middle of making this recipe right now! My house smells Heavenly!!!!
your actually supposed to add a dry white wine, I wouldn't skimp on this , its cooking for hours so the alcohol, if your worried about it , will cook off
How much wine would you add?
Where are those soup crocks fron!?
I recently found some at Bed bath and beyond
CAN'T USE THE ALCOHOL, WHAT CAN I SUB INSTEAD???
The Sherry Vinegar has no alcohol. Don’t use Sherry Wine.
the alcohol cooks off in the hours in the slow cooker
If you are allergic to alcohol still can not use it.
You can substitute with Lemon Juice or an alternative to alcohol free ingredients.
Can this be frozen?
Can this be frozen?
Never saw a reply to the question of if this can be frozen.
Absolutely you can freeze any soup that you make, but just freeze the soup and use fresh cheese with the baguette when you defrost the soup to warm it up
Yes it freezes well
I labored a long time making this only to discover I used too much brown sugar, I ruined it. It was my fault totally, I misread and thought it said two tablespoons of brown sugar. I'm going to try it again though. Don't make my mistake please~!~
I would think if you used sweet onions, you may not need sugar
I like thos post, enjoyed this onee thank you for
putting up.
How much does it make? I couldn't find that anywhere. Thanks!
It says on the top of the recipe that it yields:8 so it is for 8 persons
Can Vidalia onions be used?
I used Vidalia onions and it worked great
Sounds delicious! Can vegetable broth be used for a vegetarian version?
Thanks!
I was wondering the same thing. Either veggie or mushroom broth?
I think you could use a mushroom broth.
I just want to make sure I see this right… This recipe can take up to a full 19 hours to make? 14 hours alone for the onions, plus an additional 5 after the broth is added?
Do you have a vegetarian version?
I’m making this for the third time tonight. My modifications will be fewer onions, not sliced too thin. Thanks for a winner every time.
This is so worth the time! Oh my gosh it is delicious!
I can’t find Sherry Vinegar.
Can I use Sherry wine and how much? or what can I use instead
Soooo good and very easy!!!
I followed this recipe to a T and it was absolutely delicious! So worth the time and effort, trust me! I made this over a year ago and never forgot how amazing it tasted and turned out. It’s making my mouth water just thinking about it! Going to have to make it again real soon 🙂
Hi Patricia!
We’re so glad you enjoyed the recipe!
TSRI Team Member,
Devlyn
This was seriously so easy to make! The slow cooker did all the work, and it turned out absolutely delicious!
Hi Everly!
Glad you enjoyed our recipe!!
TSRI Team Member,
Devlyn