Crock Pot French Onion Soup

Name: Crock Pot French Onion Soup
Prep time: 10 min
Cook time: 615 min
Total time: 625 min
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; ¼ cup Wine (optional); Crusty bread; provolone, gruyere, or Swiss cheese

Dec 22, 2024 by Dan Mikesell AKA DrDan · 75 Comments

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Cooking time: 10 15

The best Crock Pot French Onion Soup has a rich beef broth and deeply caramelized onions. The easiest way to caramelize onions is by cooking them all day in a slow cooker rather than on the stovetop. The onion soup is served with toasted crusty bread and melted cheese.

🧅Ingredients

Onions
Beef broth
Butter
Seasoning—thyme, salt, pepper
Worcestershire sauce
Serving—cheese (gruyere, provolone, or Swiss) and crusty bread

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🧅Ingredients
👨‍🍳How to Make French Onion Soup in a Crock Pot—Step-by-Step Photo Instructions
🤔When is French onion soup done?
👨‍🍳Make it right every time—options and variations
↕️Crock Pot sizes
↕️Changing recipe size
📋Crock pot soup recipes
🍽️How to serve French onion soup
❄️How to store and reheating leftovers
❓FAQs
♨️Toubleshooting crock pot temperature
📖 Recipe

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!"

French onion soup is my favorite elegant comfort food; it is how I grade restaurants. Unfortunately, very few can match the deep flavor of this homemade onion soup recipe.

You can make the best French onion soup for pennies at home in almost any crock pot, from a 2-quart mini to a full-size crock pot. The caramelization takes time, so let the slow cooker do the work; you take the credit.

👨‍🍳How to Make French Onion Soup in a Crock Pot—Step-by-Step Photo Instructions

Onions with broth and seasonings for soup—labeled.

1. Chop onions into petals or rings. Separate the rings/petals into individual pieces.

Adding onion and other ingredients to the crock pot.

2. Add all ingredients except the broth to a crock pot. Cover, and cook on high for 9-10 hrs. until "softened and deep golden brown." Do not cook by time.

3. Add 4 cups of beef broth unless you use a 2-quart crock pot; add 2 cups now and 2 cups near the end of cooking.

4. Cook on high for at least one hour to combine flavors.

🍽️Serving

Adding toasted crusty bread to onion soup.

5. Arrange ramekins or oven-safe bowls on a cookie sheet. Ladle hot soup into the bowls and add toasted crusty bread on top.

6. Cover each bowl with provolone, gruyere, or Swiss cheese

7. 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.

🤔When is French onion soup done?

Watch for the endpoint of "softened and deep golden brown" for the onions being done. 9 to 10 hours on high is a reasonable estimate for most home cooks, but don't go by time alone. Crock pots vary a lot for long cooking on the high setting, so watch closely, especially if using an older or mini crock pot.

If you are unsure whether your slow cooker is reliable on high, it will take about 2 hours longer on the low setting.

👨‍🍳Make it right every time—options and variations

Quality ingredients are essential, but 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 adding red or sweeter onions like Vidalias, Mauis, and Walla Wallas.

Seasoning—The seasoning is limited to dry or fresh thyme, salt, and pepper. One to two cloves of garlic can be added to the onions. If you use unsalted butter, add a pinch more of salt.

Cheese—we like provolone, but some prefer gruyere or Swiss cheese. I like to use slices of cheese, but shredded cheese works fine.

Crusty bread or croutons: Toast buttered slices of French bread on a baking sheet in the oven or in a frying pan. Other crusty breads or large croutons may also be used to float the cheese. You can skip this step, but it is traditional and helps keep the cheese on top.

Optional—add dry sherry or dry red wine.

↕️Crock Pot sizes

This recipe makes 7 cups of soup for 4 servings. It fits nicely in a small 3-4 quart slow cooker.

2-quart mini crock pot: Technically, you shouldn't use a 2-quart crock pot since it would be over 75% full and won't cook well. However, you can still use one by adding only half the broth until the last 15 minutes. One further warning about mini crock pots: they are notorious for poor temperature control, and you will run a high chance of the onions burning—watch closely.

Full-size crock pots (over 5 quarts): Small volumes in large crock pots tend to cook a bit faster. So, check early to see how your crock pot works with this recipe.

↕️Changing recipe size

A half-recipe fits easily in a 2-quart mini crock pot, while a double recipe needs a 5-quart or larger crock pot.

To change the recipe size, change the number of servings, and use the amounts in the ingredient list, not in the directions that do not adjust.

📋Crock pot soup recipes

Let's keep that crock pot out and try other great soup recipes. Start with Ham Bone Soup, then move on to Crock Pot Broccoli Cheese Soup or Crock Pot Cheeseburger Soup.

🍽️How to serve French onion soup

It can be served as a main dish, an appetizer, or a side dish. Traditional 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.

Serve with Crock Pot French Dip Recipe for a wonderful comfort food meal. For an etiquette meal, serve it with Prime Rib Roast, Roasted Turkey Breast, or Oven Roasted Filet Mignon.

Grilled Filet Mignon

Learn How to Grill Filet Mignon to perfection in about 10 minutes. With these simple step-by-step photo instructions, you can easily cook the best-grilled filet mignon.

If served as the main dish, it should be accompanied by a fresh salad and good bread, such as Julia Child's French Bread or Easy Dinner Rolls.

❄️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

Is wine needed?

Wine is not required for onion soup. It has traditionally been used to deglaze the pan after caramelizing the onions—not needed with a crock pot. However, wine also added flavor to the soup.

Never cook with wine you don't like. If you do use wine (an option in the recipe card's tips), I suggest a non-sweet sherry, dry white, or red wine. A few suggestions: Sauv Blanc, Semillon, Pinot Grigio, Chardonnay, Merlot or Pinot Noir.

Why is it called French Onion Soup?

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.

What are caramelizing onions?

Caramelization is the browning of sugar through the oxidation of sugars. When correctly done, it results in a deep, nutty flavor and brown color—just what we need for a great soup.

Many techniques for caramelizing onions require multiple rounds of caramelization on the stovetop, which will keep you working all day at the stove. But you can do it much easier in a crock pot with this recipe.

♨️Toubleshooting crock pot temperature

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.

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.