French onion soup feels fancy, but it doesn’t need to mean standing over the stove all day. This Crockpot French Onion Soup Recipe gives you deeply caramelized onions, rich beef broth, and melted cheese over toasted bread.
The crockpot does the onion work for you—no babysitting a soup pot. It works in any size crockpot, from a 2-quart mini to a full-size slow cooker, and honestly, it beats most restaurant versions.
⏰ Quick Answer: How Long to Cook French Onion Soup in a Crockpot
- Cook the onions: 9–10 hours on high or 10–11 hours on low, until soft and deeply caramelized.
- Finish the soup: Add the beef broth and cook for 1 more hour.
Go by the onions, not just the clock—they should be deeply golden brown before adding the broth.
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- 📝 TL;DR — Recipe Summary
- 🧅 Ingredients
- 👨🍳 Quick Overview: How to Make French Onion Soup in a Crockpot
- ⏱️ How Long to Cook Onions in a Crockpot
- 👨🍳 Options and Variations
- ↕️ Changing the Recipe Size and Crockpot Size
- 📋 Crockpot Soup Recipes
- 🍽️ How to serve French onion soup
- ❄️ Storage & Reheating
- ❓ FAQs
- 📖The Recipe Card
Featured Comment by Judith:
⭐⭐⭐⭐⭐
"Will definitely be making again! It tastes just like the French onion soup from our favorite restaurant!! Thanks for a great recipe!"
📝 TL;DR — Recipe Summary
What: Classic French onion soup with caramelized onions, beef broth, toasted bread, and melted cheese.
Why: The crockpot caramelizes the onions without standing over the stove all day.
How: Cook the onions with butter and seasoning until deeply golden, add the broth for the final hour, then top with toasted bread and cheese and broil.
🧅 Ingredients
- Onions — Yellow or white onions work best. Sweet onions like Vidalia, Maui, or Walla Walla can also be used.
- Beef broth or stock — Use a good-quality broth or stock since it provides most of the soup's liquid and flavor.
- Butter — Salted or unsalted.
- Seasoning — Thyme, salt, and black pepper.
- Worcestershire sauce — Adds savory depth to the broth.
- Bread and cheese — Toasted crusty bread topped with provolone, Gruyère, or Swiss cheese gives French onion soup its classic finish.
👨🍳 Quick Overview: How to Make French Onion Soup in a Crockpot
Prep the onions: Chop the onions into petals or rings and separate them.
Caramelize: Add the onions, butter, thyme, salt, pepper, and Worcestershire to the crockpot. Cook until the onions are soft and deeply golden brown—about 9–10 hours on high or 10–11 hours on low. Go by color, not just time.
✅ Pro Tip: Always check a few hours early and give it a stir while you are there.
Add the broth: Add the beef broth and cook for 1 more hour to blend the flavors. For a 2-quart crockpot, add half the broth first and the rest near the end.
Finish and serve: Ladle into oven-safe bowls, top with toasted crusty bread and provolone, Gruyère, or Swiss cheese, then broil until bubbly and golden, about 2–4 minutes.
👇 Scroll for the printable recipe card and complete photo instructions—or keep reading for tips, variations, and serving ideas.
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⏱️ How Long to Cook Onions in a Crockpot
The onions are ready when they are soft and deeply caramelized to a golden brown. Cooking time varies between crockpots, so go by color, not just the clock.
Plan on about 9–10 hours on high or 10–11 hours on low, but check a few hours early to prevent overcooking. Once the onions are ready, add the beef broth and cook for 1 more hour to blend the flavors.
👨🍳 Options and Variations
- Garlic: Add a clove or two with the onions if you want a little garlic flavor.
- Wine: Add dry sherry, dry white wine, or red wine with the broth for additional flavor.
↕️ Changing the Recipe Size and Crockpot Size
This recipe makes about 7 cups or 4 servings and is best suited to a 3–4 quart crockpot.
- Half recipe: About 2 servings; use a 2-quart mini crockpot.
- Full recipe: About 4 servings; a 3–4 quart crockpot is the best fit.
- Double recipe: Use a full-size 6-quart or larger crockpot.
For a full recipe in a 2-quart crockpot: It will be very full. After caramelizing the onions, add half the broth, then add the remaining broth near the end.
✅ Use the serving adjustment feature in the recipe card to adjust the ingredient amounts. Use the amounts in the ingredients list, not the instructions.
📋 Crockpot Soup Recipes
🍽️ How to serve French onion soup
Serve French onion soup as a main dish, appetizer, or side. Ladle into oven-safe bowls, top with toasted French or other crusty bread, then add provolone, Gruyère, or Swiss cheese and broil until browned and bubbly.
Slices of cheese are easiest for covering the bread, but shredded cheese also works. Large croutons can replace the toasted bread.
If serving it as a main dish, a simple salad and bread are plenty.
❄️ Storage & Reheating
- Refrigerate: Store leftover soup without the bread or cheese in an airtight container for up to 4 days.
- Freeze: Freeze in meal-size portions for up to 3 months. Thaw overnight in the refrigerator.
- Reheat: Warm on the stovetop or in the microwave, then add fresh toasted bread and cheese and broil until melted and bubbly.
❓ FAQs
Yes. A half recipe fits easily. For a full recipe, caramelize the onions first, add half the broth, then add the remaining broth near the end to prevent overflowing.
No. Wine is optional in this crockpot recipe. For additional flavor, add a little dry sherry, dry white wine, or red wine with the broth.
Caramelization is the slow browning of the natural sugars in onions, producing a deep golden color and richer flavor.
For this recipe, the onions should be soft and deeply golden before you add the broth. The deeper the color without burning, the better the flavor.
📖The Recipe Card
Crockpot French Onion Soup Recipe
Video Slideshow
Ingredients
- 1½ pounds onions—white or yellow - (about 3 medium onions)
- 1 teaspoon coarse salt
- 2 tablespoons butter
- ½ teaspoon pepper
- 1½ teaspoons Worcestershire sauce
- ½ teaspoon thyme
- 4 cups beef broth
- ¼ cup wine-optional
- Crusty bread
- Provolone, Gruyère, or Swiss cheese
Step-by-Step Instructions
- Prep onions: Slice 1½ pounds of onions into petals or rings and separate into individual pieces (about 5–6 cups raw). Add to a 2-quart or larger crock pot.
- Season: Add 1 teaspoon of coarse salt, 2 tablespoons of butter, ½ teaspoon of black pepper, 1½ teaspoons of Worcestershire sauce, and ½ teaspoon of thyme. Stir to combine. (Butter may go in unmelted; stir after 1 hour or melt first.)
- Caramelize: Cook with the lid on for 9–10 hours on HIGH or 10–11 hours on LOW, until the onions are softened and deeply golden brown. Check a few hours early and go by color, not just time—stir when checking. Then add 4 cups of beef broth—if using a 2-quart crock pot, add only 2 cups now.
- Simmer: Cook on high for at least 1 hour to allow the flavors to combine. If using a 2-quart, add the remaining 2 cups of broth about 15 minutes before the end.
- Toast & assemble: Toast crusty bread (brushed with butter) in the oven or a frying pan. Arrange ramekins or other oven-safe bowls on a sheet pan. Ladle hot soup into bowls and float the toasted bread on top.
- Cheese: Cover each bowl with provolone, Gruyère, or Swiss cheese.
- Broil until the cheese is bubbly and golden, 2–4 minutes.
Recipe Notes
Pro Tips
Doneness: The onions are ready when softened and deeply golden brown. Check a few hours early and go by color, not just the clock. Crockpot size: As written, a 3–4-quart crockpot is best. A half recipe fits a 2-quart mini; use a 6-quart or larger crockpot for a double recipe. 2-quart crockpot: For a full recipe, add only half the broth after the onions caramelize, then add the rest near the end. Bread and cheese: A crusty French baguette or large croutons work well. Provolone, Gruyère, or Swiss cheese are good choices. Broth: Use good-quality beef broth or stock since it provides much of the soup's flavor. Wine: Optional—add ¼ cup dry sherry, dry white wine, or red wine with the broth. Storage: Refrigerate without bread and cheese for up to 4 days or freeze for 3-4 months.Your Own Private Notes
To adjust the recipe size:
You can adjust the number of servings above; however, only the amount in the ingredient list is adjusted, not the instructions.
Nutrition Estimate (may vary)
Editors Note: Originally published July 12, 2015. Updated with expanded options, refreshed photos, and a table of contents to help navigation.
Angels Berry says
Omgosh this is good!!! I am a one person household and I wanted some French Onion soup so I adjusted the ingredient amounts and used a small slow cooker. When it was done I put some in a serving bowl, added some grated Gouda (what I had on hand) and homemade croutons… oh yes!!! My new go-to!!!
Melanie Z says
This recipe seems so simple and easy. I always have seen recipes calling for red onion and we can't digest them, so this will be perfect to try very soon!
Thank you for sharing all your tips too. They are extremely helpful:)
Melanie
Mickey says
Instead of plain beef broth try using Campbells Beef Consume , it has some extra added flavor , plain beef broth just dosent it have , making your soup taste like you’re used to it tasting
Jan says
Do you use the same amount of the consume?
Mary Schaefer says
I have several French Onion Soup recipes, and this is by far the best. It is also the easiest. It will now be a regular in my winter rotation.
Thanks,
Mary
DonnieC says
I made this yesterday and it came out really well. I was quite surprised at the intensity of the flavour of the caramelised onions. I’m glad I chose to make this on a day when I was staying home as it is a slow cooker recipe that requires some attention.
My cooker does run hot so I heeded the advice and periodically peeked in to see how the onions were fairing towards the end of their nine hour cook time. I probably should have looked closer as there were a few heavily charred pieces at the end. I just picked them out prior to adding the beef broth.
I will make this again but will either make a point of giving the onions an occasional stir towards the end of their cooking time or turn down the heat for the last hour or so.
Dan Mikesell AKA DrDan says
Hi Donnie,
Welcome to the blog.
I do love this recipe but the variability in slow cookers can lead to some problems. About stirring, it is fine but may increase the cooking time some since it will take a while for the crock pot to get back up to temp.
Dan
Laurie says
Thank you Dr.Dan. This recipe is my winter go to. You’re right, quality ingredients are the key. Love the no fuss of the onions.
Dan Mikesell AKA DrDan says
Hi Laurie,
Welcome to the blog.
This is one of my favorites. Thanks for the note and rating.
Dan
Debby Stark says
What do I need to do with the broth to get it warm enough to keep it from cracking the crockpot?
Dan Mikesell AKA DrDan says
Hi Debby,
Welcome to the blog. If room temperature broth cracks your crock pot, it was a crock pot problem.
Frozen things like frozen chicken can crack a ceramic crock pot which is part of the reason for never putting frozen meat (or I guess frozen broth also) in a crock pot to cook.
Dan
Nancy says
Will the onions carmelize with the crock pot lid on? Can't wait to try this recipe and surprise my husband.
Dan Mikesell AKA DrDan says
Hi Nancy,
Lid on. I just add that to the recipe. The only crock pot recipe I have with (I think...) the lid off is the crock pot fudge.
Dan
Deborah Lein says
Dr Dan, what does te recipe mean by 'coarse salt'? Table salt? no-iodine table salt? Kosher salt? (I'm sure you don't mean road salt which looks nasty and is the coarsest I've ever seen. Deb L
Dan Mikesell AKA DrDan says
Hi Deborah,
I started using the term coarse salt a few years ago instead of typing out Kosher or sea salt all the time. So nothing special. If table salt is used, cut it back a little. And please always use iodized salt, I have seen enough goiters in my life.
Have a great holiday season.
Dan
Celesti says
Followed the recipe as written and the French Onion soup was a hit. I did use the yellow onions and the flavor was wonderful. The only change will be using my larger crock pot to cook down the onions. I used a smaller crock pot, and when I added the beef broth the liquid came to the top of the pot. My choice of cheese was Gruyère and the flavor complimented the dish. It was so good I had to share this site to several of my friends. Thank you for sharing a French Onion soup recipe that is easy to follow, make and serve.
Bllue says
I can hardly wait to try this recipe! It's a bit warm for it right now. I discovered your site on Facebook in the "Cooking For One or Two" page. I rarely look at that since I now use YOUR site!
I noticed a typo in step 4: "float toasted crusty bread on sou" - I think that should be "soup." :)
Dan Mikesell AKA DrDan says
Hi Bllue,
Welcome to the blog. Glad you are enjoying the blog and thanks for the proof read—fixed.
Enjoy the soup.
Dan
Judith says
Made this last night for supper. Will definitely be making again! It tastes just like the french onion soup from our favorite restaurant!! Thanks for a great recipe!
Judith says
Was I supposed to stir the onions, butter, etc. together before turning on the crockpot?
Dan Mikesell AKA DrDan says
Hi Judith,
Welcome to the blog.
Yes, stir together. I will add that to the text.
Dan
Anita says
My daughter gifted us with a 7 qt crock pot. It's just the two of us so I hate to double the recipe. What adjustments should I make? Just shorter time? Looks easy and we both love onion soup! Thanks
Dan Mikesell AKA DrDan says
Hi Anita,
Welcome to the blog.
Cooking in a bigger crock pot is generally just fine but because there is less mass in the cooker, it will cook a bit faster. You will see in the instructions about cooking to an nicely browned onions due to variability of crock pots. So cook to the endpoint not by time and check a few times early.
Hope that helps.
Dan
Kirsten says
I'm guessing since I doubled the recipe, I should also increase the cook time once the stock/broth is added. Your thoughts?
Dan Mikesell AKA DrDan says
Hi Kristen,
No, I would not increase that time, but an hour is the minimum, like all soups, a bit longer simmering is good. The biggest variable it the cooking time of the onions due to crock pot variables.
Dan