Crock Pot French Onion Soup is an easy and economical way to make classic French onion soup at home without standing at the stove all day. With rich buttery caramelized onions in a rich broth, topped with toasted crusty bread and melted cheese.
🧅Ingredients
Onions
Beef broth
Seasoning—thyme, salt, pepper
Worcestershire sauce
Serving—cheese (gruyere, provolone, or Swiss) and crusty bread
Jump To (scroll for more)
- 🧅Ingredients
- 👨🍳How to Make Crock Pot French Onion Soup—Step-by-Step
- Make it right every time—options and variations
- Related recipes you will love
- ↕️Crock pot size and making this a "for two" or "family size " recipe
- How to serve French onion soup
- How to store and reheating leftovers
- ❓FAQs
- How to caramelize onions
- ♨️About the crock pot and troubleshooting
- 📖 Recipe
Featured comment from Judith:
"Will definitely be making again! It tastes just like the French onion soup from our favorite restaurant!! Thanks for a great recipe!"
This elegant comfort food is better than most restaurants, and you made it for pennies at home. It's perfect for a small crock pot or doubled to make a family size.
French Onion Soup is more than beef broth with onions. It takes time to get the caramelization going well, so let the slow cooker do the work.
👨🍳How to Make Crock Pot French Onion Soup—Step-by-Step
1. This recipe fits in a 2-quart mini crock pot and works well in a 3-4 quart crock pot. A bigger crock pot may cook faster, so pay attention to color.
2. Chop 1 ½ pounds of onions into petals or slices, about 3 medium-sized onions. Some people will want rings or petals—add to a 2 ½ quart or larger crock pot. If doubling the recipe, 5 quarts or a larger crock pot are needed. Triple needs larger than 6 quarts.
3. Add 1 teaspoon of coarse salt, 2 tablespoons of butter, ½ teaspoon of black pepper, 1 ½ teaspoons Worcestershire sauce, and ½ teaspoon of thyme. Then, stir them together. The butter can go in unmelted, but you must stir in 1 hour or melt it in the microwave.
4. Cook on high for 9-10 hours with the lid on until it is nicely darker brown. Be warned that some crock pots may run hot. Please watch for the endpoint of "softened and deep golden brown" for the onions being done, and don't go by time alone. Then add 4 cups of beef broth.
5. Cook on high for at least one hour to combine flavors.
6. Preheat the broiler to high. Arrange ramekin or oven-safe bowls on a cookie sheet. Ladle hot soup into the bowls and float toasted crusty bread on the soup.
7. Cover each bowl with the cheese of your choice.
8. Broil until cheese is bubbly and golden, 2-4 minutes.
For more details, keep reading. See the Recipe Card below for complete instructions and to print.
Make it right every time—options and variations
Quality ingredients are important with so few ingredients—only use ingredients you trust. I like to use Lee and Perrins®️ Worcestershire Sauce and Swanson®️ beef broth or stock.
Onions—Regular yellow or white onions are the best choices, but some like to add red onions or sweeter onions like Vidalias, Mauis, and Walla Wallas.
Seasoning—The seasoning is limited to some dry or fresh thyme with salt and pepper. One to two cloves of garlic can be added to the onions.
Cheese—gruyere, provolone, Swiss, or gruyere cheese are preferred. But even mozzarella cheese will work.
Crusty bread or croutons—toast a buttered slice of French bread on a baking sheet in the oven. Large croutons may also be used.
Crockpot—crock pots can vary on long high cooking, so please do not cook the onions by time only the first time; watch for the cooking endpoint—you want deep golden brown.
Related recipes you will love
Let's keep that crock pot out and try other great soup recipes. Start with Ham Bone and Bean Soup, then move on to Crock Pot Broccoli Cheese Soup or Crock Pot Cheeseburger Soup.
Serve with Crock Pot French Dip for a wonderful comfort food meal. For an etiquette meal, serve it with Prime Rib Roast, Roasted Turkey Breast, or Oven Roasted Filet Mignon.
↕️Crock pot size and making this a "for two" or "family size " recipe
This recipe makes 7 cups (4 servings) and fits in a 2 ½ quart or larger crock pot but not a 2 quart mini crock pot. You may make a half recipe in a 2-quart mini-crock pot, but watch the color and endpoint of cooking. They may have temperature control issues for long cooking times.
A double recipe should be cooked in a 5 quart or larger crock pot.
- Use the recipe card and adjust the number of servings.
- Use the amount of ingredients in the ingredient list, not the instructions—those do not adjust.
How to serve French onion soup
It can be served as a main dish, an appetizer, or a side dish. It is traditionally served in a small oven-safe soup bowl, like a ramekin, topped with browned cheese and supported by croutons or a slice of crusty bread.
For the cheese, we like provolone, but some prefer gruyere or Swiss cheese. I like to use slices of cheese, but shredded cheese works fine. Again, quality matters.
For the bread, use a nice crusty French baguette if available. Other crusty breads or large croutons may also be used to float the cheese. You can skip it, but it is traditional and helps keep the cheese on top.
How to store and reheating leftovers
Leftover soup (without the bread or cheese) should be sealed airtight and refrigerated for 4 days or frozen for 3 months.
Frozen French onion soup should be thawed overnight in the refrigerator before reheating. It can be reheated on the stovetop or in the microwave. Then, add toasted crusty bread and cheese before browning under the broiler.
❓FAQs
Wine is not required for onion soup. It has traditionally been used to de-glaze the pan after caramelizing the onions—not needed with a crock pot. But the wine also added flavor to the soup.
Never cook with wine you don't like. If you are using wine (an option in the tips of the recipe card), I suggest a non-sweet, dry white, or red wine. A few suggestions: Sauv Blanc, Semillon, Pinot Grigio, Chardonnay, Merlot or Pinot Noir.
French Onion Soup is from France in the 18th century; this traditional French soup can be used as an appetizer or a main course. Part of the reason for the initial popularity was that onions were cheap and readily available.
How to caramelize onions
Caramelization is the browning of sugar through the oxidation of those sugars. It results in a deep nutty flavor and brown color when correctly done. Just what we need for a great soup
Many techniques require multiple rounds of caramelization on the stovetop, which will keep you working all day at the stove. But you can do it in a crock pot. I'm lazy. I pick number two.
Start by loading a slow cooker with chopped or sliced onions. Cook with butter, salt, pepper, and thyme. Add a little Worcestershire sauce to deepen the beefy flavor. Cook on high for 9-10 hours, but depending on your crock pot, this may be a few hours less or more.
♨️About the crock pot and troubleshooting
On all crock pots (slow cookers), the maximum temperature on both low and high should be in the 212° range, but it will take different times to get there. That is all controlled by a thermostat that has improved over the years but can still malfunction.
If you use a full-size crock pot for this smaller recipe, you have less material to heat, and it may cook faster. Mini-crock pots are known for temperature control issues.
Nine to ten hours on high is consistent with other crock pot French onion soup recipes and less than the 10-12 hrs recommended by American Test Kitchen (subscription required).
If you question your crock pot or use a very small, large, or older one, please watch the endpoint when caramelizing onions—you want deep golden brown.
This recipe is listed in these categories. See them for more similar recipes.
Have you tried this recipe, or have a question? Join the community discussion in the comments.
📖 Recipe
Crock Pot French Onion Soup
Video Slideshow
Ingredients
- 1 ½ pounds onions—white or yellow - about 3 medium size onions
- 1 teaspoon coarse salt
- 2 tablespoons butter
- ½ teaspoon pepper
- 1 ½ teaspoon Worcestershire sauce
- ½ teaspoon thyme
- 4 cups beef broth
- ½ cup Wine - optional
Finishing then serving
- Crusty bread
- Cheese of choice for topping
Instructions
- This recipe fits in a 2-quart mini crock pot and works well in a 3-4 quart crock pot. A bigger crock pot may cook faster, so pay attention to color.
- Chop 1 ½ pounds of onions into petals or slices, about 3 medium-sized onions. Some people will want rings or petals—add to a 2 ½ quart or larger crock pot. If doubling the recipe, 5 quarts or a larger crock pot are needed. Triple needs larger than 6 quarts.
- Add 1 teaspoon of coarse salt, 2 tablespoons of butter, ½ teaspoon of black pepper, 1 ½ teaspoons Worcestershire sauce, and ½ teaspoon of thyme. Then, stir them together. The butter can go in unmelted, but you must stir in 1 hour or melt it in the microwave.
- Cook on high for 9-10 hours with the lid on until it is nicely darker brown. Be warned that some crock pots may run hot. Please watch for the endpoint of "softened and deep golden brown" for the onions being done, and don't go by time alone. Then add 4 cups of beef broth.
- Cook on high for at least one hour to combine flavors.
- Preheat the broiler to high. Arrange ramekin or oven-safe bowls on a cookie sheet. Ladle hot soup into the bowls and float toasted crusty bread on the soup.
- Cover each bowl with the cheese of your choice.
- Broil until cheese is bubbly and golden, 2-4 minutes.
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Recipe Notes
Pro Tips
- Be advised that some crock pots may run hotter so watch for softened and deep golden brown as the endpoint for the onions being done. I would say if your crock pot ever boils on low, it may be in the "runs hot" category, then use low for this recipe. More discussion in the post.
- Also, using a much larger crock pot for this small recipe may cook a bit faster.
- Please check the onions halfway through due to the above.
- This recipe can be easily doubled but could also be cut in half.
- This makes about 6 cups of soup. I call that 4 servings of 1 ½ cups each.
- As written, use a 2 ½ to 4-quart crock pot. For a double recipe, you will need 5quart or more. A half recipe will fit a 2 quart mini crock pot.
- Some type of crusty bread is used to float cheese on top. You can use what you want, but a nice crusty French baguette is my choice. For the cheese we like provolone, but some prefer Gruyere or Swiss.
- Quality matters here in the choice of broth. Do not cheap out on generic.
- Wine can be added to the soup with the broth. A half cup would be about the right amount. Suggestions discussed in the post.
- Good refrigerated for 3-4 days and 3-4 months frozen.
Your Own Private Notes
To adjust the recipe size:
You may adjust the number of servings in this recipe card under servings. This does the math for the ingredients for you. BUT it does NOT adjust the text of the instructions. So you need to do that yourself.
Nutrition Estimate
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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