Crockpot French Onion Soup + Video
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Crockpot French onion soup has all of the flavor of your favorite bistro. Make it at home with fresh ingredients for a fraction of the cost.
This slow cooker 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, 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.
Crockpot French Onion Soup
- Onions – While the sweet ones are preferred, you can get away with any “white” variation.
- 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.
- 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.
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FAQ – Common Recipe Questions
Want to reduce the cooking time?
Brown the veggies 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.
Is 4 hours on High the same as 8 hours on Low?
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.
Do you need to saute onions before slow cooking?
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!
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Watch the video below to see how easy it is to make this recipe!
Crockpot French Onion Soup + Video
- 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
- 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.
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 February 2021
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.
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
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?
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!!!