Slow Cooker Cabbage & Onion Soup
A hearty, simple slow-cooker cabbage and onion soup with a rich savory broth. This version is naturally vegetarian if you use vegetable broth, and it can easily be made lower-sodium.
Ingredients
Makes: 6–8 servings
Prep time: 20 minutes
Slow-cook time: 6–8 hours LOW or 3–4 hours HIGH
1 large head green cabbage, about 2–2½ lb
2 large yellow onions, thinly sliced
3 carrots, sliced
3 celery stalks, sliced
3 cloves garlic, minced
6 cups low-sodium vegetable or chicken broth
1 can (14.5 oz) diced tomatoes, with juices
2 tablespoons tomato paste
1 tablespoon olive oil
1–2 teaspoons Worcestershire sauce
1 teaspoon dried thyme
1 teaspoon dried parsley
½ teaspoon black pepper
½ teaspoon smoked paprika, optional
1 bay leaf
1–2 teaspoons salt, only as needed after cooking
1 tablespoon lemon juice or apple cider vinegar, optional
Optional onion-soup flavor
For a stronger French-onion-style flavor, add:
1 packet dry onion soup mix, preferably reduced-sodium
Important: If using onion soup mix, start with no additional salt. Many packaged mixes are already very high in sodium.
Instructions
1. Prepare the vegetables
Remove the outer leaves from the cabbage and cut it into quarters. Remove the tough core and chop the cabbage into roughly 1-inch pieces.
Slice the onions, carrots, and celery.
2. Optional—but highly recommended: brown the onions
Heat the olive oil in a large skillet over medium heat.
Add the onions and cook for 8–12 minutes, stirring occasionally, until softened and beginning to turn golden.
Add the garlic during the final minute.
This extra step gives the soup substantially more flavor, but you can skip it if you want a true dump-and-go recipe.
3. Load the slow cooker
Add to the slow cooker:
Cabbage
Carrots
Celery
Cooked onions and garlic
Diced tomatoes
Tomato paste
Broth
Worcestershire sauce
Thyme
Parsley
Black pepper
Smoked paprika, if using
Bay leaf
Onion soup mix, if using
Stir everything together.
The cabbage may seem like far too much at first. That’s normal—it shrinks considerably as it cooks.
4. Cook
Cover and cook:
LOW: 6–8 hours
HIGH: 3–4 hours
The soup is ready when the cabbage is tender and the onions and carrots are soft.
5. Finish the soup
Remove the bay leaf.
Taste the broth and adjust the seasoning. Add salt only if necessary.
For a brighter flavor, stir in 1 tablespoon lemon juice or apple cider vinegar just before serving.
Optional Additions
Make it more filling
Add one of these during the last part of cooking:
1 can drained white beans
1 can drained kidney beans
1 cup cooked shredded chicken
1 lb browned ground beef
½–1 cup cooked barley
Make it creamy
Stir in ½ cup heavy cream during the final 15–20 minutes.
Make it spicy
Add:
½ teaspoon red pepper flakes
¼–½ teaspoon cayenne
Hot sauce to taste
Make it more like French onion soup
Use beef broth, caramelize the onions well, and serve each bowl with toasted bread and melted Swiss or Gruyère cheese.
Approximate Nutrition
Nutrition varies substantially depending on the broth, onion soup mix, oil, and serving size.
For 1 of 8 servings, without onion soup mix:
Nutrient Approx. amount
Calories 130–160
Protein 5–6 g
Total fat 4–5 g
Saturated fat <1 g
Carbohydrates 22–25 g
Fiber 6–7 g
Sugars 10–12 g
Sodium ~300–500 mg
Potassium ~600–750 mg
With packaged onion soup mix
The sodium can increase dramatically, depending on the brand. For a lower-sodium soup, use low-sodium broth and season the soup yourself with onion powder, garlic powder, thyme, pepper, and a little Worcestershire sauce instead.
Nutrition & Allergen Q&A
Q: Is cabbage soup healthy?
A: It can be a very nutrient-dense, low-calorie meal. Cabbage provides fiber, vitamin C, vitamin K, and other plant compounds, while the carrots, onions, celery, and tomatoes add additional nutrients.
Q: Is this soup gluten-free?
A: It can be, but check the labels on broth, Worcestershire sauce, and onion soup mix. Some packaged onion soup mixes contain wheat or other gluten-containing ingredients.
Q: Is it dairy-free?
A: Yes, the basic recipe is dairy-free. Don’t add cheese or cream if you need it to remain dairy-free.
Q: Is it vegetarian?
A: Yes, when made with vegetable broth and a vegetarian/gluten-free Worcestershire alternative if necessary. Traditional Worcestershire sauce often contains anchovies.
Q: Is it vegan?
A: Use vegetable broth and a vegan Worcestershire sauce, and don’t add meat, cream, or cheese.
Q: Is cabbage soup good for weight loss?
A: It can fit well into a calorie-conscious diet because it provides a large volume of vegetables and fiber for relatively few calories. It isn’t a special “fat-burning” food, though.
Q: Can I eat this every day?
A: You can include it regularly, but it’s best as part of a varied diet. If you’re using packaged onion soup mix, watch the sodium.
Q: Can I freeze it?
A: Yes. Cool it promptly, portion it into airtight containers, and freeze. The cabbage may become somewhat softer after thawing, but the soup freezes well.
Q: How long does it keep in the refrigerator?
A: Generally 3–4 days when refrigerated promptly in a covered container.
Q: Can I make it without tomatoes?
A: Absolutely. Replace the tomatoes with another 1–1½ cups of broth. The result will be a lighter, more onion-and-cabbage-forward soup.
Q: Why is my cabbage still crunchy?
A: It simply needs more cooking. Slow cookers vary, and large cabbage pieces take longer. Continue cooking until it reaches your preferred tenderness.
Q: Can I use red cabbage?
A: Yes. It works, although it will give the broth a darker, purplish color.
Q: Can I use bagged shredded cabbage?
A: Yes. It’s an excellent shortcut. You may need roughly 2–3 bags (about 12–16 oz each) depending on how cabbage-heavy you want the soup.
Best version
For the most flavorful result, I’d use caramelized onions + low-sodium beef or vegetable broth + fresh cabbage + carrots + celery + tomatoes, and skip the salty onion-soup packet. The soup will taste homemade rather than overly salty while still having a strong onion flavor.
