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.
Liz Kelly says
So good and easy to make.
I used an organic, gluten free, low sodium off the bone beef broth. Highly recommend, the flavor is perfect.
Nushka says
This is one of my favourite recipes from the blog. Easy to make and so delicious.
Katie says
Hi. My husband and I love this soup recipe. It's my go to base for making Beef French Dip.
However, in reading the instructions, you might want to make an edit in either step 1 or 2 on the crockpot.
Thanks for a keeper recipe!
Dan Mikesell AKA DrDan says
Hi Katie,
Welcome to the blog and thanks for the proofread. It didn't need the repeat about the crock pot size.
Hope you enjoy the soup.
Thanks for the note and rating.
Dan
Patti says
What is your feelings about beef stock as opposed to beef broth? I’ve found that in the case of chicken stock, it’s not only tastier, but the sodium content is so much lower (50 mg), that it’s good for heart healthy diets. You have to add salt to bring out the flavor of whatever you are making, but it’s in your control, and you aren’t starting with 450 to 700 mg. (estimates based on what I’ve seen) to start with. Even low sodium broths aren’t great. I haven’t looked for beef stock specifically, I usually use chicken stock, but I love French Onion Soup, so either way, it’s going in my tummy!
Dan Mikesell AKA DrDan says
Hi Patti,
Welcome to the blog.
Like many things, it depends on usage. In chicken broth vs stock, I can tell a minimal difference. But in beef, I personally can not detect a difference in what I use in taste. Years ago, beef broth was bad but is much better in recent years.
Regarding sodium, you can get stock/broth with anywhere from zero to full sodium. So it is a matter of personal choices and any health concerns. If you have no medical issues, the normal sodium ones are generally fine. If you have a medical issue, the amount of sodium restriction you should have should be determined by you and your doctor.
For my taste, I'm usually happy with some decrease in sodium.
For this recipe, you should use beef since that is a huge part of the taste and the Worcestershire sauce help boost that but is also relatively high in sodium but the low sodium version not quite as good. Years ago, when the beef products were so poor, we would use vegetable broth and more Worcestershire sauce.
Thanks for the note.
Dan
Olivia says
I made this yesterday. However, I got impatient after about 6 hours in the crockpot and I'm glad I did! The onions were about to burn! I think it's really important to check the onions in the middle incase your crockpot cooks quickly. After the 6 hours, I skipped to the instructions to add the broth and cook another hour and it turned out wonderfully! Thanks!
DrDan says
Hi Olivia,
Welcome to the blog.
Glad you checked it. Crock pots are so variable.
Cooks Illustrate suggest 12 hours on high. I think my 9-10 hr is good for the vast majority of crock pots. I did just add another warning about crock pot variabilities and suggested a fast peak at 6 hours since most people don't know their crock pots well.
Thanks for the note and the rating.
Dan
karin says
Best French onion soup I ever had! Definitely making again!!
DrDan says
Hi Karin,
Welcome to the blog.
I many times judge a restaurant on their onion soup. Most fail. I think this one passes.
Thanks for the note and rating.
Dan
Angie says
Wow! This soup was so amazingly delicious and easy. I think we just found our new New Year's tradition -this easy yet fabulous soup!!!! The family absolutely loved it!
DrDan says
Hi Angie,
Welcome to the blog.
I do love French onion soup and this is so simple.
Thanks for the note.
Dan
Thomas says
This was absolutely delicious! I personally needed it to be ready for a late lunch the next day. So I added my onions and unmelted butter, cooked on high for about hour and half; mixed my butter then dropped it to low for the remaining 16 hours. I had just a couple darker onions not quite burnt, otherwise almost all the onions were perfectly carmalized! I added my broth for two hours on low rather then the hour high. And it turned out perfect!
DrDan says
Hi Thomas,
Welcome to the blog.
Thanks for the description of your technique. Hopeful others will find it useful. I think as long as you get a good caramelization on the onions it will do well.
Thanks for the note and Happy New Years.
Dan
Sarah Newman says
Absolutely wonderful soup. Mine took between 7-8 hours to be ready in the slow cooker. Definitely a new favorite in my house. Thank you!
Kristine says
Just made this and OMG it tastes sooo good! I only have a large crockpot, so I started watching the onions around 7 hours. I only had one can of beef broth but had a packet of Au Jus (followed the directions) and added it. Wow, the flavors of the onions combined with the beef stock are friggin amazing. I'm skipping bread for a bit, so I just added some mozz cheese. I live on Maui, so the weather really never gets chilly, but this hearty soup brings back so many nice memories of living in colder weather (many years ago). Thanks so much!
Donna J G says
Can I choose to make on stove top?
DrDan says
Hi Donna,
Yes but no. This recipe is a derivative of several stovetop and crockpot recipes. The stovetop recipes all seemed to require lots of babysitting all day long. So much work. If you just do a fast stovetop caramelization of the onions, your soup will be lacking. So yes you can but I suggest using an actual stovetop recipe
Dan
DONNA SEAGO says
I made this yesterday............I doubled the recipe...................everyone loved it.............couldn't have been easier.........
DrDan says
Hi Donna,
I have done this one over and over.
Thanks for the note.
Dan
Vince Juliano says
Hi Dr Dan,
This looks like a Godsend for an oldie moldie newly single guy. I'll keep you posted on my successes......and failures.
Thank you so much.
cory says
I was flipping through a bunch of recipes on google because the original video and recipe i was referring to were very different cooking instructions from eachother!?
So i basically just decided to wing it. Then i found this recipe and its like exactly what i concocted! Put my heart at ease knowing its going to still be great.
DrDan says
Hi Cory,
Welcome to the site. Somewhat like you, I see a recipe I'm interested in but then research the heck out of it the simplify,
Dan
joan says
Recently made this. Turned out great. So much easier than slowly cooking onions on the stove. 9 hours on high was good. Will be making onion soup a lot more now.
DrDan says
Hi Joan and Happy Holidays
This does turn out a great soup. Once you know your crock pot, this is a put it on in the morning and have a great dinner type recipe.
Thanks for the note.
Dan
Melanye says
Does the cook time change if using a larger crock pot?
DrDan says
General rules are that too small may prolong cooking time if more than 75% full. Too big is usually considered fine. BUT here we are prolonged cooking on high. I would expect it to cook faster. And if you have one of those pots that boils on low (IE a hot pot) we could be burning the onions. If in doubt, cook on low and look for the end point of soft and deep golden brown.
Dan