Caramelized Onion Soup with Cider Syrup

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This amazing Caramelized Onion Soup is made more delicious with a swirl of cider syrup.

caramelized onion soup in a white bowl

If you’re a fan of French Onion Soup, then you’ll probably like this Caramelized Onion Soup too. Caramelized onions are sweet and melt-in-your-mouth wonderful, so translate that into soup and that’s what we’ve got here. It’s a smooth, blended soup with great fall flavors.

ingredients displayed for making caramelized onion soup

Ingredients needed for Caramelized Onion Soup:

  • yellow onions
  • butter
  • olive oil
  • beef broth
  • fresh apple cider
  • fresh thyme
  • white sugar
  • Parmesan cheese

How to make cider syrup:

The cider syrup used in this recipe is made using the simple process of reducing apple cider by boiling it in a saucepan. You’ll start with 2 cups of apple cider and boil that down to 1/3 cup, which will result in a syrup-like consistency.

caramelizing onions in soup pot

How to Caramelize Onions:

Butter and oil are heated together in the soup pot. Thinly sliced yellow onions are added to the pot. Since onions break down a lot when cooked, you’ll be using a lot of onions (about 5). The onions are cooked over medium-high heat for about 20 minutes. Stir them often, and they’ll start turning brown and shrivel up as it shows in the photo above.

showing process of making caramelized onion soup in soup pot

How to turn caramelized onions into soup:

After you’re done caramelizing the onions, you’ll add beef broth and apple cider to the onions in the pot. Then you’ll add several fresh thyme sprigs, a tiny bit of sugar and salt/pepper. The soup is then simmered for 30 minutes. Once the simmering is done, you’ll want to pull it off the heat and let it cool off a bit. Then you’ll process all of it in a food processor until it’s smooth in texture.

caramelized onion soup in white bowls with bread on side

Garnish bowls of soup with a drizzle of the cider syrup, a sprinkle of Parmesan cheese and a few fresh thyme leaves.

close up peek of caramelized onion soup in a white bowl bread on side

What to serve with caramelized onion soup:

Pick up the best crusty French bread you can find in your town. It’ll be good for dunking in this delicious soup! Serve it with a side salad and some white wine. Or you can opt to serve Caramelized Onion Soup in cups as a side to roasted chicken or pork. It’s even a nice little starter for your Thanksgiving dinner. Enjoy!

Here are a few more soup recipes you might like to try:

caramelized onion soup in a white bowl
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Caramelized Onion Soup

Awesome with a drizzle of cider syrup!
Prep Time 45 minutes
Cook Time 1 hour
Servings 6 servings
Calories 239kcal
Course Soup
Cuisine American
Keyword caramelized onions, soup



  • 2 cups fresh apple cider


  • 2 pounds yellow onions (about 5 medium onions)
  • 2 tablespoons unsalted butter
  • 2 tablespoons extra virgin olive oil
  • 3 cups beef broth
  • 2 cups fresh apple cider
  • 1 bunch fresh thyme
  • 1/2 teaspoon granulated white sugar
  • salt and freshly ground pepper, to taste
  • 6 tablespoons freshly grated Parmesan cheese



  • In a small saucepan, add 2 cups of cider and bring to a boil. Continue to cook over high heat until the cider is reduced to 1/3 cup, about 20 minutes.


  • Peel the onions and cut them in half through the root end. Place the flat end on a cutting board. Cut into very thin slices, less than 1/8-inch thick.
  • In a large, heavy pot, heat the butter and oil until the butter is melted. Add the onions and cook over medium-high heat, stirring frequently, until they soften and get very dark brown (some will blacken), about 20 minutes. Add the broth and cider and bring to a rapid boil.
  • Lower the heat and add 5 long thyme sprigs, sugar, salt and freshly ground black pepper to taste. Cook, covered, for 30 minutes over medium heat, stirring often.
  • Remove the thyme sprigs from the soup and pull the soup off the heat and let it cool down a bit. Then transfer the soup to the bowl of a food processor. Be careful not to fill the bowl of the processor too full. Super hot soup may splash out of the processor, so be careful! Process until very smooth; this should take several minutes since you're processing onions! Add salt and pepper to taste and transfer the soup to 6 soup bowls. Drizzle each with some of the cider syrup and garnish with fresh thyme leaves and a sprinkling of cheese.


  • *Be sure to use fresh, unpasteurized apple cider from the refrigerated case in the supermarket.
  • *If you are preparing this recipe as gluten-free, just be sure to use a brand of beef broth that is know to be free of gluten.


Serving: 1serving | Calories: 239kcal | Carbohydrates: 33g | Protein: 5g | Fat: 11g | Saturated Fat: 4g | Cholesterol: 14mg | Sodium: 536mg | Potassium: 451mg | Fiber: 3g | Sugar: 22g | Vitamin A: 192IU | Vitamin C: 14mg | Calcium: 113mg | Iron: 1mg
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  • Lisa, UK wrote:

    This is truly gorgeous. It was called Soup from Heaven when I made it last night!

    (for the Britishers, cider = fresh, pressed apple juice, not Cider as we know it)