Table of Contents
Zucchini and Yellow Squash Soup has lots of flavor from rosemary and Parmesan and this tasty low-carb soup is perfect for fall! And this zucchini soup can be made in the Instant Pot or on the stove!
PIN the Zucchini Soup recipe to make it later!
This delicious low-carb Zucchini and Yellow Squash Soup is a recipe that has a lot of sentimental value for me. I first made it when Lisa of Homesick Texan sent me the link to a zucchini soup recipe (that’s no longer online) and told me how delicious it was, and I adapted the recipe to be lower in carbs. And I was making soup back then because I had just gotten braces on my teeth!
Now flash forward years later and I’m enjoying this Zucchini Soup with my nice straight teeth. And now I’ve got a collection of Instant Pot Recipes on the blog and I’d use that method to make the soup more quickly.
Not to worry though, if you don’t have an Instant Pot you can make this zucchini soup recipe on the stove. And it’s still zucchini and summer squash season for a few more weeks, and I think using those summer veggies in a soup is a perfect way to transition into fall, so I’m reminding you about this delicious soup for Friday Favorites this week, enjoy!
What ingredients do you need for this recipe?
- Olive Oil (affiliate link)
- yellow onion
- Minced Garlic (affiliate link)
- Italian Herb Seasoning (affiliate link)
- chopped fresh rosemary or frozen rosemary (see notes)
- green and yellow summer squash
- vegetable stock or chicken stock (or broth)
- salt and fresh-ground black pepper to taste
- freshly grated Parmesan cheese, for serving
What if you don’t have fresh or frozen rosemary?
If you don’t have fresh rosemary or frozen rosemary, I would recommend using a small amount of ground rosemary (affiliate link) to flavor the soup.
What if you don’t have two colors of summer squash?
It will change the color a bit, but you can definitely make this recipe with all yellow summer squash or all green zucchini if that’s what you have.
What Size Instant Pot Did I Use?
I use a 6 Quart Instant Pot (affiliate link) for all my Instant Pot Recipes! You can find more Instant Pot Recipes on my other site, Slow Cooker or Pressure Cooker.
Want more soup recipes that use zucchini?
Check out Low-Carb and Keto Soups with Zucchini Noodles or Spectacular Low-Carb Soups with Zucchini to see lots more tasty ideas for using zucchini in soup!
How to make Zucchini and Yellow Squash Soup:
(Scroll down for complete printable recipe including nutritional information.)
- Chop up an onion, finely chop the rosemary, and mince up a tablespoon of fresh garlic. (You can use dried or frozen rosemary if you don’t have fresh, but be sure to chop it very small so you don’t bite into a big piece of rosemary. And of course fresh herbs are always best!)
- Turn the pressure cooker to Saute (or medium-high heat for a stovetop pressure cooker or soup pot.) Add the olive oil and butter and heat until butter is melted and the pan is hot, then add the onion and cook 3-4 minutes. Then add the finely chopped rosemary, minced garlic, and Italian Herb Blend and cook about 3-5 minutes more.
- Add the chicken or vegetable stock and let it simmer for about 10 minutes, long enough to get the onion/garlic/rosemary flavors into the stock.) Be sure to use the reduced amount of stock if you’re using a pressure cooker. I kept the pressure cooker setting on Saute for this, but on the stove I’d reduce the heat to medium.
- While the stock simmers, chop up the zucchini and yellow squash until you have about 8 cups of diced squash (or slightly less if your pressure cooker won’t hold that much.)
- In the pressure cooker, add the squash, lock the lid in place, choose MANUAL, HIGH PRESSURE and set the time for 5 minutes. The use quick release method to release the pressure. (On the stove add the squash and simmer over medium-low or low heat about 30 minutes, or until the squash is very soft and the flavors are well blended.)
- Here’s how my squash looked after 5 minutes at high pressure.
- Then I used my Immersion Blender (affiliate link) to puree the soup. You could do this in a food processor or blender if you don’t have an immersion blender, but be careful with the hot liquid. (Use the same process to puree the stovetop soup after it’s cooked for about 30 minutes.)
- Then you’ll need to simmer the soup to reduce it until it’s as thick as you’d like, probably about 20 minutes on the stovetop or in the pressure cooker. (I simmered on Saute so it cooked down more quickly.) Here’s how my soup looked after it has been reduced.
- Season to taste with salt and fresh-ground black pepper and serve hot, with plenty of freshly-grated Parmesan to add at the table.
More Zucchini Soup Recipes to Try:
(Some may not be low in carbs; check nutritional information)
Low-Carb Turkey Soup with Zucchini Noodles
Italian Sausage, Zucchini and Macaroni Soup
White Bean Soup with Italian Sausage, Zucchini, and Basil
Slow Cooker Zucchini e Fagioli Soup
Ground Turkey, Mushroom, and Zucchini Noodle Soup
Weekend Food Prep:
This recipe has been added to a new category called Weekend Food Prep to help you find recipes you can prep or cook on the weekend and eat during the week!
- 2 T olive oil
- 1 T butter (see notes)
- 1 yellow onion, chopped
- 1 T minced fresh garlic
- 1 tsp. Italian Herb Blend
- 4 tsp. chopped fresh rosemary or frozen rosemary (see notes)
- 8 cups diced green and yellow summer squash
- 6 cups vegetable stock or chicken stock
- salt and fresh-ground black pepper to taste
- fresh grated Parmesan cheese, for serving
- Chop the onion, mince the garlic, and finely chop the fresh rosemary.
- Heat olive oil and butter in large heavy soup pot or stovetop pressure cooker (or in the bottom of the electric pressure cooker on the Saute setting).
- Then add onion and saute about 5 minutes, or until onion is translucent and softened.
- Add garlic, rosemary, and Italian Herb Blend and cook 3-5 minutes more.
- While the onion, garlic, and rosemary are cooking, chop up enough zucchini and yellow squash to make 8 cups (or slightly less for the electric pressure cooker if you can’t fit that much.)
- Add the vegetable or chicken stock to onion mixture and simmer 10 minutes. (Use 6 cups stock for pressure cooker or 8 cups for stovetop.)
- For the electric pressure cooker I kept the setting on Saute to simmer the stock.)
- Then add chopped zucchini and yellow squash.
- For stovetop cooking, turn heat to very low and simmer 30 minutes, or until squash is very soft and flavors are well blended.
- For electric or stovetop pressure cooker, lock the lid, choose MANUAL, HIGH PRESSURE and set the time for 5 minutes.
- Use the quick-release method to release the pressure after the time is up.
- Use an Immersion Blender (affiliate link) to puree the mixture, or work in batches and puree in food processor or blender. (Be careful if you’re using the blender or food processor and don’t fill them too full when blending hot liquids.)
- When mixture is as pureed as you’d like it, check the consistency of the soup.
- Simmer until the soup is reduced and as thick as you’d like it. (Simmer about 20 minutes on medium low on the stovetop or stovetop pressure cooker or about 20 minutes on Saute in the electric pressure cooker.
- This time may vary, depending on how thick you want it.)
- Season to taste with salt and fresh-ground black pepper.
- Serve soup hot, with freshly grated Parmesan cheese sprinkled on top if desired.
You can use all olive oil if you don’t want butter. You can use frozen rosemary if you have some. You can also use a small amount of ground rosemary (affiliate link) to flavor the soup if you don’t have fresh or frozen rosemary.
I use my own homemade chicken stock but you can definitely use canned chicken broth (affiliate link). I used 6 cups of stock and slightly less than 8 cups of diced squash to make this in my electric pressure cooker. You will need about 2 cups more stock for stovetop cooking.
Recipe inspired by soup recipe from Epicurious.com.
Amount Per Serving:
Calories: 147Total Fat: 8gSaturated Fat: 2gUnsaturated Fat: 5gCholesterol: 7mgSodium: 855mgCarbohydrates: 7.8gFiber: 4gSugar: 9gProtein: 4g
Nutrition information is automatically calculated by the Recipe Plug-In I am using. I am not a nutritionist and cannot guarantee 100% accuracy, since many variables affect those calculations.
Low-Carb Diet / Low-Glycemic Diet / South Beach Diet Suggestions:
Everything used here is a low-glycemic and low-carb ingredient, making this soup great for any low-glycemic or low-carb eating plan, including Keto. If you’re following South Beach you could replace the butter with more olive oil if you wish or you can use even more butter for low-carb or Keto.
Find More Recipes Like This One:
Use Soups to find more recipes like this one. Use the Diet Type Index to find recipes suitable for a specific eating plan. You might also like to follow Kalyn’s Kitchen on Pinterest, on Facebook, on Instagram, on TikTok, or on YouTube to see all the good recipes I’m sharing there.
Historical Notes for this Recipe:
This recipe was posted in 2008 when I’d just gotten braces on my teeth! I’ve been making it ever since, and it was last updated with more information in 2022.
We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites. As an Amazon Associate, I earn from qualifying purchases.