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
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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.
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.
Lisa Huff says
Oh wow, this looks so good!
Mary says
I've had mine cooking for 2 hrs so far and my house smells Ah-MAZING! Can't wait for dinner tonight.
Mary says
It didn’t disappoint! No burnt onions even cooking on high for 9 hrs. Perfectly carmalized and a fantastic soup!
Emily says
I made this recently and it was SO easy and delish! I ended up buying jarelsburg cheese. I will make this again for sure!
DrDan says
Thanks for the note. It is one of my favorite soups.
Dan
Chris says
At what point to you add the ingredients from 2nd crock pot? 😊
DrDan says
No second crock pot. Carmalize onions then add broth and cook some more. Then is ready to put into bowls with bread and cheese.
Dan
Colette Watts says
Before I make this can you freeze the soup.
Tks
DrDan says
Yep
Cera says
Cut a huge portion of time off by quickly caramelizing your onions in butter prior to adding to the crock pot. Adds a ton more flavor and onions are not mush.
Paige says
What kind of cheese and bread do you prefer to use? And how much of each?
DrDan says
I like a crusty French or Italian bread with Provolone cheese. About 1/2 to 3/4 inch thick slice of the bread to cover the dish and just enough cheese to cover also.
Jennifer says
Should I use yellow onions??
DrDan says
Yellow or white.
Nicole says
So I'm like Dan, mine burned a lil. I started it at 730am, it is now 111pm can i add the broth and let it sit on low all day? The onions are pretty camerlized but my husband and son don't get home till about 5pm
DrDan says
I think some crock pots run too hot for this recipe on high. With your pot, do low next time. Remove from heat now since they are caramelized and refrigerate. Then about an hour and a half before you need it, add the broth and cook on low. It does need to simmer some with the broth and not just reheat.
Willie Mitchell says
Sound delious.. Only thing I dislike onions ?
Dr. Horshenschwartz (from the clinic) says
Excellent. Made it a couple months ago, making it again today with 6 pounds of onions. Smells amazing!
Dan says
You must have a typo. When you cook onions on high for 9 hours you get burnt onions. I know because I did it. I'm mad that I didn't use my own common sense. You should change that to say LOW for 9 hours. Please fix this so others like me dont have their whole house smelling of burnt onions.
DrDan says
Hi Dan...
Sorry it didn't work well for you but high is correct. I did it twice and 9 hours on high worked great in two different pot I have. I check some references before I replied and they are all over the place. 8 hours on low to 14 hours on high. Cooks Country does high for 10-12 hours...
So what went wrong. 1) your crock pot runs hot and/or 2) some variation in the onions.
I'm putting an advisory on the recipe stating to cook to "softened and deep golden brown". You want the caramelization.
Thanks for the note
DrDan
Paula Mencucci says
I had the same problem. Burnt onions....I'm sad because I use the crockpot when I"m not home to cook and when I come home after a long day to ruined dinner, I'm extremely disappointed :( Apparently my crockpot runs hot, but only on one side...
DrDan says
Hi Paula,
I changed some wording about hot pots. I believe it was Crock Pot brand that had the heating element located in one location near the front if I remember right and not around the pot. They had a lot of localized burning from what I understood.
The warning I added about hot pots was if you see boiling when cooking on low, then you should assume a hot pot. On low a crock pot should be 207 or less. Most run right at 200. It is harder to measure the temperature on high since it should be about 250 but some pots run 300. Since both are above the boiling point you can't get an accurate measurement without special equipment. That, of course, does not address hot localized spots.
Again, sorry you had an issue.
Dan
Kathy Heiber says
This is delicious....I have always loved French Onion Soup and now I can have it whenever I want....YAY!!!
rating...+10
Peg says
Do you leave it covered or open?
DrDan says
Covered.
Steven House says
I LOVE french onion soup, but rarely make it since caramelizing the onions is almost a day long affair. For some reason I never considered using my crock pot. I can't wait to try this. Many thanks!
Cheryl S. says
LOVE the onion soup. Even my very picky 10 year old gave it a definite thumbs up! Who knew it could be so easy?!?
DrDan says
Thanks for the note and rating. I have repeated this several times.