Bity
The first pot of slow cooker minestrone soup I made properly was an accident. I had a fridge drawer of odds and ends, a tin of cannellini beans, and no intention of standing over a hob. Seven hours later the house smelled like a trattoria and I had lunch sorted for four days.
Slow cooker minestrone soup is really a method rather than a fixed recipe, which is why it suits the pot so well. The vegetables soften without turning to mush, the beans give up a little starch and thicken the broth, and the tomatoes lose their tinny edge completely.
Quick Breakdown
Why You’ll Love This Slow Cooker Minestrone Soup
- It feeds six to eight from store cupboard bits. Two tins of beans, one of tomatoes, and whatever vegetables are looking sad.
- Naturally vegan as written. Because it uses vegetable stock and no cheese, everyone at the table can eat it.
- It gets better overnight. In fact, day two minestrone is a genuinely different and deeper soup.
- Only one pan to wash. The vegetables get a quick sauté, then everything moves to the pot.
- It freezes properly. Meanwhile you can leave the pasta out and add it fresh later.
Ingredient Notes
- Cannellini beans. Two tins, drained and rinsed. They break down just enough to give the broth body, and the Academy of Nutrition and Dietetics has a good primer on cooking with beans if you want to swap in borlotti or butter beans.
- The soffritto. Onion, carrot and celery. However, do give them their five minutes in the pan first, since raw onion never quite loses its bite in a slow cooker.
- Tinned chopped tomatoes. One 400 g tin. That is deliberately restrained, because minestrone is a vegetable soup with tomato in it rather than a tomato soup.
- Courgette. Added at the start here. It softens right down and thickens the broth, so do not expect firm cubes.
- Small pasta. Ditalini, orzo or anything tiny. It goes in for the last half hour only.
- Spinach or kale. Stirred in at the very end, off the heat, so it wilts rather than boils grey.
Why You Should Cook the Pasta Separately
This is the one thing that separates good minestrone from a pot of thick starchy porridge on day two. Pasta keeps drinking liquid long after the heat is off, so a batch that was perfect at dinner will have swollen into paste by lunchtime tomorrow.
If you are eating the whole pot in one sitting, stir the pasta straight into the slow cooker for the last 30 minutes as the recipe says. So far so simple.
If you are batch cooking, though, boil the pasta in a separate pan and keep it in its own tub. Then add a spoonful to each bowl as you reheat. As a result every portion tastes like it was made that morning.
Is Minestrone Meant To Be Vegan?
Traditionally it is not, since most Italian versions lean on a parmesan rind dropped into the pot or a scatter of grated cheese at the table. That rind is where a lot of restaurant minestrone gets its savoury depth.
This version skips it, and honestly it does not need rescuing. The two tins of beans, the sautéed soffritto and a full litre of vegetable stock do the heavy lifting instead. A tablespoon of lemon juice at the end lifts everything the way cheese otherwise would.
That said, if you eat dairy, a parmesan rind in the pot for the last two hours is a lovely addition. Just fish it out before serving.
How To Make Slow Cooker Minestrone Soup
1. Soften the base. First heat the olive oil in a frying pan and cook the onion, carrot and celery for five to seven minutes, until they have lost their raw edge.
2. Bloom the herbs. Next stir in the garlic, oregano, thyme, salt and pepper and give it 30 seconds, just until the kitchen smells of it.
3. Move it over. Then tip the whole panful into the slow cooker, scraping in every last bit.
4. Add the rest. After that add the chopped tomatoes, drained beans, diced courgette, vegetable stock and water, and stir well.
5. Cook it slowly. Cover and cook on LOW for 6 to 7 hours, or HIGH for 3 to 4 hours.
6. Pasta, then greens. Meanwhile stir the pasta in for the final 30 minutes. Finally add the chopped spinach or kale, let it wilt for two minutes, and finish with the lemon juice.
Slow Cooker Minestrone Soup Mistakes to Avoid
- Adding the pasta at the start. Six hours in liquid turns it into wallpaper paste. Thirty minutes is plenty.
- Skipping the sauté. Because a slow cooker never gets hot enough to caramelise anything, that five minutes in the pan is where the savoury base comes from.
- Too much tomato. One tin. More than that and you have made a thin tomato soup with vegetables in it.
- Boiling the greens. Spinach and kale need two minutes at the end, not two hours.
- Forgetting to season at the end. Still, taste before serving. Beans and pasta both soak up salt.
Tips for the Best Slow Cooker Minestrone Soup
- Dice everything for the slow cooker minestrone soup to roughly the same size. As a result each spoonful has a bit of everything rather than one giant lump of carrot.
- Keep a little stock back to loosen the soup when you reheat it.
- A parmesan rind, a strip of pancetta or a spoonful of pesto all add depth if you are not keeping it vegan.
- The lemon juice at the end is not optional in my kitchen. It wakes the whole pot up.
- Save the bean liquid from one tin if you like a thicker broth, then stir a splash in near the end.
Storage and Reheating
- Fridge. Slow cooker minestrone soup keeps for up to 4 days in an airtight container. However, expect the pasta to keep swelling, so add extra stock when you warm it.
- Freezer. Up to 2 months, and best frozen before the pasta goes in. Then cook fresh pasta when you thaw it.
- Reheating. Gently on the hob with a splash of stock or water. Meanwhile a microwave is fine for single bowls.
Variations and Substitutions
- Extra vegetables. Green beans, potatoes and diced peppers all work. Harvard’s Nutrition Source makes the case for mixing colours rather than sticking to the same three.
- Gluten free. Use gluten free pasta added at the very end, or leave the pasta out and add a diced potato instead.
- Heartier. Brown a little Italian sausage with the soffritto. For a meatier soup with the same slow cooker logic, try my slow cooker Italian wedding soup.
- Better stock. Homemade makes a real difference here, and instant pot chicken stock takes 45 minutes if you are not keeping it vegan.
- Beanier still. Add a third tin and mash half of it against the side of the pot for a thicker broth, the way I do with instant pot chili.
What to Serve With Minestrone
Slow cooker minestrone soup wants bread, and plenty of it. Warm sourdough dinner rolls torn and dunked into the broth are the version I make most often, though a garlic rubbed baguette slice is quicker.
Otherwise keep it simple. A sharp green salad with a lemony dressing cuts through the tomato, and a bowl of grated parmesan on the table lets everyone decide for themselves.
Frequently Asked Questions
Method and Ingredients
Can you cook minestrone soup in a slow cooker?
Yes, and it suits one better than most soups. Slow cooker minestrone soup gives the beans and vegetables hours to soften while the tomato loses its sharpness completely.
How do I make traditional minestrone in a slow cooker?
Sauté the onion, carrot and celery first, then add tomatoes, beans, courgette and stock and cook on LOW for 6 to 7 hours. Pasta and greens go in at the end.
Can I add other vegetables?
Of course. Green beans, potatoes, peppers and leeks all belong here, since minestrone was designed around whatever was in the garden.
Can I make it gluten free?
Yes. Use gluten free pasta stirred in right at the end, or leave the pasta out and add a diced potato with the other vegetables instead.
Storage and Troubleshooting
Why did my soup go thick and stodgy?
The pasta kept absorbing liquid after cooking. So cook it separately if you plan on leftovers, and loosen each bowl with a little extra stock.
Can I freeze slow cooker minestrone soup?
Yes, for up to two months. Freeze it before the pasta goes in for the best texture, then boil fresh pasta when you reheat.
Does it need to be vegan?
Not at all, it just happens to be. Add a parmesan rind during cooking or grate cheese over the top if you eat dairy.
Ingredients
- 2 tablespoons olive oil 30 ml
- 1 large onion diced, 200 g
- 2 carrots diced, 150 g
- 2 stalks celery diced, 100 g
- 3 cloves garlic minced, 15 g
- 1 teaspoon dried oregano
- 1/2 teaspoon dried thyme
- 1 teaspoon salt
- 1/2 teaspoon black pepper
- 1 400 g tin chopped tomatoes
- 2 400 g tins cannellini beans drained and rinsed, about 480 g drained
- 1 medium courgette diced, 200 g
- 1 litre vegetable stock
- 500 ml water
- 100 g small pasta ditalini or similar
- 100 g fresh spinach or kale chopped
- 1 tablespoon lemon juice optional, 15 ml
Instructions
- Heat the olive oil in a frying pan over medium heat.
- Add the onion, carrots and celery and saute for 5 to 7 minutes until slightly softened.
- Stir in the garlic, oregano, thyme, salt and black pepper and cook for 30 seconds until fragrant.
- Transfer the mixture to the slow cooker, scraping in every last bit.
- Add the chopped tomatoes, cannellini beans, courgette, vegetable stock and water. Stir well.
- Cover and cook on LOW for 6 to 7 hours, or HIGH for 3 to 4 hours.
- About 30 minutes before serving, stir in the pasta and cook until tender.
- Stir in the chopped spinach or kale and cook until wilted.
- Add the lemon juice if using, then taste and adjust the seasoning.
