Minestrone Soup
Published November 14, 2021 • Updated March 6, 2026
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This low carb soup is pure comfort on a chilly day. Instead of kidney beans, I use lupini beans (only 8g net carbs) and simmer a parmesan cheese rind in the broth for that deep, savory flavor you can't get any other way.
I started making this keto minestrone because I missed the big, brothy Italian soups I grew up eating. Regular minestrone is loaded with pasta and kidney beans, so I had to rethink the whole thing. The parmesan cheese rind is what makes this version work. It melts slowly into the broth over 20-plus minutes and gives the soup a savory depth that you’d swear came from simmering all day. I keep a bag of rinds in my freezer specifically for soups like this and my keto beef tomato soup.
The other piece that makes this different from most low carb vegetable soups is the lupini beans. I’ve gotten more questions about these beans than almost any other ingredient on the site. They’re naturally firmer than cannellini or great northern beans, and that’s intentional. They hold their shape through simmering, through reheating, through everything. Cannellini fall apart after a day in the fridge. Lupini don’t. One reader (Rita) told me she’d been making traditional minestrone with cannellini for years and actually prefers this version now. That was a big compliment.
I use cauliflower rice instead of pasta or regular rice, which keeps the carb count down without leaving the soup thin. You barely notice the swap once everything has simmered together. The bacon adds smokiness, but if you want a vegetarian version, swap it for 2 tablespoons of olive oil and use vegetable broth. I’ve done it both ways and the parmesan rind carries enough flavor on its own.
One thing I’ve learned from making this dozens of times: don’t add the spinach until the very end. It wilts in about 30 seconds and overcooking it turns the whole pot a muddy green. Same goes for freezing. If you’re meal prepping, leave the spinach out of the batch you’re freezing and stir in fresh leaves when you reheat. The soup itself freezes well for up to 3 months.
If you’re into keto soups, this pairs well with a rotation. I cycle through this, my keto chicken and rice soup, keto turkey soup, and keto cheeseburger soup depending on the week. This one is my go-to when I want something lighter but still filling.
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Ingredients
2 slices bacon, diced or 2 tablespoons olive oil -
1/2 cup diced onions
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1/2 cup diced carrots
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3 stalk celery, diced
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2 medium zucchini, diced
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28 oz can whole tomatoes
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4 cup chicken broth, vegetable broth or water
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1 parmesan cheese rind, about 1x4”
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1 cup cauliflower rice
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1 cup lupini beans
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3 cups spinach leaves
Step by Step Instructions
Step by Step Instructions
Cook bacon
Add bacon to a large stock pot or Dutch oven. Cook over medium-high heat until cooked but not crispy.
Add some vegetables
Add diced onions, carrots and celery to the pot and continue cooking until almost tender.
Simmer with cheese rind
Add chicken broth or vegetable broth, 1 teaspoon salt, zucchini, tomatoes and parmesan rind. Bring to boil, then reduce heat to a simmer. Let cook uncovered until vegetables are tender (at least 20 minutes).
Add rice and beans
Add cauliflower rice, lupini beans and cook for 5 minutes.
Nutrition disclaimer
The nutrition information provided is an estimate and is for informational purposes only. I am a Doctor of Pharmacy (Pharm.D.); however, this content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always consult your physician or other qualified health provider before making any lifestyle changes or beginning a new nutrition program.
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Get My Macros + Recipes →Frequently Asked Questions
Do lupini beans need to be peeled before adding to the soup?
I don't peel mine. The ones I buy (jarred) come ready to use. Some brands sell them with the outer casing still on, so if yours look like they have a thick skin, just pinch it off. But in this recipe, I toss them in straight from the jar.
Can I make this in the Instant Pot?
I haven't tested this one in the Instant Pot specifically, but the method would be straightforward. Saute the bacon and vegetables using the saute function, then add everything except the spinach, cauliflower rice, and lupini beans. Pressure cook on high for 8 minutes with a quick release. Stir in the cauliflower rice, lupini beans, and spinach at the end using the saute function for 5 minutes.
Why are my lupini beans still firm after cooking?
I've answered this one a lot. Lupini beans are naturally firmer than regular soup beans, and that's how they're supposed to be. They won't turn soft and creamy like cannellini. I actually prefer the texture because they hold up through reheating without falling apart. If you want them a bit softer, simmer longer or try them from the freezer the next day. I've noticed frozen leftovers have noticeably softer beans.
Can I make this minestrone vegetarian?
I've made it both ways. Swap the bacon for 2 tablespoons of olive oil and use vegetable broth instead of chicken broth. The parmesan rind does most of the heavy flavor work, so you won't miss the bacon as much as you'd think. Keep in mind parmesan isn't technically vegetarian (it uses animal rennet), so if that matters, use a vegetarian hard cheese.
How do I store and freeze leftover minestrone?
I store mine in the fridge for up to 5 days. For freezing, I leave the spinach out of whatever portion I'm freezing and stir in fresh spinach when I reheat. The soup freezes well for up to 3 months. Leave room in the container for expansion.
How do I reheat frozen minestrone without it getting mushy?
I thaw mine overnight in the fridge, then reheat on the stovetop over medium heat. The vegetables hold up well since they were firm when frozen. Add a splash of broth if it's thickened. The lupini beans actually get softer after freezing and thawing, which I think improves them.
Can I add more vegetables to this recipe?
I've had readers add bell peppers, green beans, and even radishes. Orange and yellow bell peppers work well since they're lower carb and add color. Green beans are great if you toss them in with the zucchini. One reader tried radishes and I was curious how they'd hold up. Just adjust cooking time so everything gets tender, and keep an eye on your carb count if you're adding higher-carb vegetables.
Two parmesan rinds instead of one. Trust me. The broth gets this almost meaty depth a single rind just doesn't hit. Still tweaking the seasoning balance, but that change alone made it worth making again.
Writing that down. I've always stopped at one but the meaty depth you're describing is exactly what I want from that broth.
First time making homemade soup and had no idea what lupini beans were (couldn't even find them at first), but the broth ended up with this depth I couldn't explain. The parmesan rind, right? Is there a way to tell when it's done or do you just leave it in the whole time?
Leave it in the whole time. It won't fully dissolve but gets soft and kind of melty by the end. Just fish it out before you serve. That depth you tasted is almost entirely the rind.
I'll be honest, I was skeptical about lupini beans in a minestrone. Been making minestrone for years with cannellini and couldn't imagine the texture would be close. But the broth with that parmesan rind is so rich and savory that it kind of doesn't matter, and the lupini held up better than I expected, not mushy at all. Way fewer carbs than my usual version and I actually prefer it now.
The rind really does carry the whole broth. And yeah, lupini hold up in a way cannellini honestly don't, especially after reheating. Cannellini get kind of soft and fall apart. Lupini stay intact.
I've just gone KETO and can't wait to try this recipe. Thanks!
The lupini beans are worth tracking down. They keep it at 8g net carbs and don't turn mushy like regular beans do.
Good flavor. Like others have said, the beans were hard and not especially tasty even cooking them longer. I had to salt and pepper quite a bit. I also threw in orange and yellow bell pepper and a few chopped up radishes. I used a cauliflower/broccoli rice blend. Will be nice to have a hot lunch this week!
Orange and yellow bell peppers are a great add. The radishes are interesting, do they hold up or get soft? I've never tried them in soup.
Delicious soup. The beans were hard and will have the cook (hubby) leave out next time. They came in a jar and we were surprised how hard they were. The bean hardness did not detract from the rest of the delicious soup. Cook made a double batch. The leftover soup had softer beans after freezing. My daughter liked the beans from the get go. Go figure.
Freezing does that, more time to hydrate. Lupini beans are just naturally firmer than what most people expect from a soup bean, even fully cooked. Leaving them out is fine too.
We replicated this recipe this evening for dinner and found it to be a wonderful, low carb minestrone soup. This was also our first time using lupini beans and found them in this recipe a little more crunchy than expected. I am uncertain as this is the first time I've used them whether they would soften if put in during the 20 minute simmer. The other big change we made was instead of bacon. We browned up diced spam and I felt that it should have gone in with the with the cauliflowered rice and so the next time we do this recipe I will try that out and get back with you. Thanks for the recipe!
Mine weren't crunchy. Not as soft as a regular bean. You can always cook it longer and I'm sure they will soften up. Glad you liked the recipe!
Do you have to peel the lupini beans? The bean usually has a hard casing on them? I haven't made yet, so will come back to give rating after.
I didn't peel mine. They might have already been peeled.