Easy, Summery Zucchini-Basil Soup Recipe

This delicious, pesto-adjacent zucchini soup is perfect for a late-summer lunch or light dinner, comes together quickly, and can be served hot and cold.

By
J. Kenji López-Alt
Kenji Lopez Alt
Culinary Consultant
Kenji is the former culinary director for Serious Eats and a current culinary consultant for the site. He is also a New York Times food columnist and the author of The Food Lab: Better Home Cooking Through Science.
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Updated October 06, 2023

Why It Works

  • Leeks are a mild onion that complements mild zucchini perfectly.
  • Adding basil in two stages gives you layers of basil flavor.

If you've ever grown your own zucchini, you've probably had the same problem I've had: There's just way too much of it. Nobody grows pounds and pounds of zucchini because they want to make great zucchini bread. Zucchini bread exists solely for the purpose of using up all that excess zucchini we get each summer. The magic of zucchini bread is that it doesn't feel forced. Nobody questions why there's zucchini in there; they just enjoy it.

Overhead view of zucchini-basil soup, garnished with basil leaves and olive oil.

Serious Eats / J. Kenji López-Alt

Here, then, I offer a second recipe that uses up a ton of great summer zucchini without figuratively shoving it down our throats, though one might literally want to do so after tasting it.

The great thing about this zucchini-basil soup is that it cooks so darn quickly. Zucchini is a very watery vegetable, with a weak, almost spongy structure that breaks down rapidly during cooking. This is frequently an obstacle when you're preparing zucchini, but here, it's a positive: It means we can cook the zucchini until it's tender enough to blend, while retaining its bright green color for a soup that's both tasty and attractive.

I start by sautéing some leeks and celery in extra-virgin olive oil. A lot of people will tell you not to cook with extra-virgin olive oil, but, as we've seen time and time again, with mildly flavored dishes like this, sautéing in extra-virgin olive oil will make a significant difference in the final flavor.

Once the leeks and celery are tender, I add a few cloves of minced garlic, which I sauté until fragrant, then a pound and a half of zucchini. If you want to keep your relationship with overgrown zucchini pure, you can use those giant ones you find toward the end of the summer. But if you prefer a soup that tastes a little better, go for smaller, denser zucchini, which have less water and more flavor.

I like to add the basil in two separate batches, which produces a layered flavor. The first handful I add with the zucchini, before covering everything with water and letting it simmer until the zucchini is tender. The second handful I add right at the end, just before I purée the whole pot's worth with a handheld immersion blender.

Overhead view of the finished zucchini-basil soup, served in a wooden bowl and garnished with basil leaves and olive oil.

Serious Eats / J. Kenji López-Alt

The combination of garlic, basil, and olive oil means the soup ends up tasting deliciously like pesto, but with zucchini's mild vegetal flavor holding it together and making it a meal. Not that I couldn't sip down a bowl of straight-up pesto, mind you.

Closeup of zucchini-basil soup.

Serious Eats / J. Kenji López-Alt

From start to finish, it takes just about 20 minutes or so. That's good news, because we're gonna need all the free time we can get to hatch creative ways to use the rest of the summer's zucchini.

June 2017

Recipe Details

Easy, Summery Zucchini-Basil Soup Recipe

Cook 25 mins
Active 20 mins
Total 25 mins
Serves 4 to 6 servings
Cook Mode (Keep screen awake)

Ingredients

  • 2 tablespoons (30ml) extra-virgin olive oil, plus more as needed and to serve

  • 1 large leek, finely diced (about 8 ounces; 225g)

  • 3 medium ribs celery, finely diced (about 6 ounces; 170g)

  • Kosher salt

  • 3 medium cloves garlic, minced (about 3/4 ounce; 25g)

  • 1 1/2 pounds (700g) zucchini, split lengthwise and cut into 1/2-inch disks (see note)

  • 2 cups packed fresh basil leaves, roughly chopped (about 2 ounces; 55g), divided

  • 5 cups (1.2L) water

  • Freshly ground black pepper

  • Fresh juice from 1 lemon, to taste

Directions

  1. Heat olive oil in a large saucepan or saucier over medium heat until shimmering. Add leek and celery. Season with salt and cook, stirring, until vegetables are softened but not browned, about 5 minutes. If pan starts to look dry at any point, add a small splash of olive oil. Add garlic and cook, stirring, until fragrant, about 30 seconds. Add zucchini and cook, stirring, for 1 minute. Add half of basil, stir to combine, and add water.

  2. Bring to a simmer and cook, stirring occasionally, until zucchini is tender but still bright green, about 10 minutes. Add remaining half of basil and blend soup using a handheld immersion blender or a countertop blender until it is as rough or as smooth as you like it. Season to taste with salt, black pepper, and lemon juice and serve, drizzling with additional olive oil at the table.

    The simmered zucchini, leek, and basil is puréed with an immersion blender directly in the pot.

    Serious Eats / J. Kenji López-Alt

Special Equipment

Immersion blender or countertop blender

Notes

Use young, firm zucchini for this recipe; larger zucchini will be more watery. The soup can be served hot, but is also delicious chilled on a hot day.

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Nutrition Facts (per serving)
89Calories
5gFat
11gCarbs
3gProtein
×
Nutrition Facts
Servings: 4 to 6
Amount per serving
Calories89
% Daily Value*
Total Fat 5g7%
Saturated Fat 1g4%
Cholesterol 0mg0%
Sodium 252mg11%
Total Carbohydrate 11g4%
Dietary Fiber 3g10%
Total Sugars 4g
Protein 3g
Vitamin C 32mg159%
Calcium 79mg6%
Iron 1mg8%
Potassium 495mg11%
*The % Daily Value (DV) tells you how much a nutrient in a food serving contributes to a daily diet. 2,000 calories a day is used for general nutrition advice.
(Nutrition information is calculated using an ingredient database and should be considered an estimate.)

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