The first pot I ever made of this had a slick of orange fat floating on top like a parking lot puddle.
My wife stirred it once, looked at me, and said nothing at all.
That silence did more damage than an actual review would have.
The kale had gone the color of an army blanket, which did not help my case.
So I made it again the following week and changed exactly two things.
I poured the sausage fat out of the pot before I built anything else in it.
And I kept the kale on the cutting board until the last four minutes.
Same ingredients, completely different bowl.
What you want here is a thin, clear, golden broth you can see the bottom of the bowl through.
Not creamy. Not thick. Brothy.
The sausage goes in as browned coins instead of crumbles, so you can actually see it sitting in there.
The sweet potato holds its cubes rather than dissolving into the liquid.
And the kale stays dark green and slightly toothy, in wide ribbons, not olive mush.
I make this about twice a month once the weather turns cold.
It runs forty five minutes from cold pot to full bowl, most of which is unattended simmering.
Get the fat out early and the greens in late, and it comes out right every single time!
Why This Soup Works
This is a brothy soup, and everything below exists to keep it that way. Most versions online drift toward creamy, which buries the three ingredients you came for.
- Thin golden broth. Clear enough to see the cubes sitting on the bottom. Eight cups of chicken broth and nothing to thicken it.
- Sausage coins, not crumbles. Half inch slices brown on two flat faces and stay visible in the finished bowl. Crumbles vanish into the liquid within a minute.
- Cubes that hold. Three quarter inch sweet potato at a bare simmer, never a rolling boil.
- Late kale. Four minutes in the pot. Long enough to soften, short enough to stay dark green.
- Fat poured off. One tablespoon stays, the rest goes. This is the difference between a broth and a slick.
Sound fussy? It's two extra minutes of work.
What Kind of Sausage to Use
Italian pork sausage links are what I reach for, and I buy them mild. The soup gets its heat from red pepper flakes instead, so I can dial it up or down without buying a different package.
- Mild Italian pork links. My default. Fennel and garlic already in the mix, and enough fat to brown properly.
- Hot Italian pork links. Use these and cut the pepper flakes in half.
- Chicken or turkey Italian sausage. Leaner, so add a splash more olive oil to the pan. You will have almost no fat to pour off.
- Andouille. Smokier and firmer. It changes the soup into something more Cajun, and I like it.
- Bulk sausage. It works, but you lose the coins. If bulk is what you have, roll it into small meatballs instead of crumbling it.
Pro tip: chill the links for fifteen minutes before slicing and they cut into clean coins instead of squashing.
What You Need
- Italian sausage links (1 lb). Sliced into ½ inch coins.
- Olive oil (1 tablespoon). Just enough to start the sausage rendering.
- Yellow onion (1). Diced. Sweet onion works and goes softer.
- Garlic (4 cloves). Minced. Four is not a typo, the broth is thin and needs the support.
- Red pepper flakes (½ teaspoon). The whole heat budget.
- Dried thyme (1 teaspoon). Or three fresh sprigs pulled out at the end.
- Sweet potatoes (1 ½ lb). Peeled and cut into ¾ inch cubes. Bigger than you think, they shrink.
- Chicken broth (8 cups). Low sodium, because the sausage is already salty.
- Lacinato kale (1 bunch). Ribs stripped, leaves torn into wide ribbons. Curly kale works and needs an extra minute.
- Apple cider vinegar (2 teaspoons). Stirred in off the heat. It lifts the whole pot.
- Heavy cream (¼ cup, optional). Only if you want it. It costs you the clear broth, so I usually skip it.
How to Make It
Step 1: Brown the Sausage Coins
Heat the olive oil in a heavy pot over medium high and lay the coins flat in a single layer.
Leave them alone for 3 to 4 minutes until the underside is genuinely browned, then flip.
Work in two batches if the pot is crowded. Crowded sausage steams instead of browning.
Lift the coins out to a plate.
Step 2: Pour Off the Fat and Build the Base
Pour off all but about 1 tablespoon of the fat in the pot.
This is the step everyone skips and it is the whole reason your broth stays clear.
Add the onion to what is left and cook 5 minutes until soft.
Add the garlic, pepper flakes and thyme and stir for 30 seconds, until it smells like something.
Step 3: Simmer the Sweet Potato
Add the sweet potato cubes and the broth, and return the sausage coins to the pot.
Bring it up to a bare simmer, then hold it there for 15 to 18 minutes.
A bare simmer means lazy bubbles at the edge, not a rolling boil.
Test a cube with a knife tip. It should give with no resistance and still be a cube.
Step 4: Kale In at the End
Stir in the kale ribbons and set a timer for 4 minutes.
Pull the pot off the heat, stir in the vinegar, then salt and pepper it properly.
Taste it. A thin broth needs more salt than you expect.
Getting the Kale Right
Kale is the only ingredient here with a short window, so treat it like one. Everything else in the pot is forgiving.
- Strip the ribs. Fold the leaf in half and run a knife down the spine, or just pull the leaf off with your fingers. The rib stays woody no matter how long it cooks.
- Tear wide. Two inch ribbons. Small pieces disappear into the broth and you lose the look entirely.
- Four minutes, no more. Set an actual timer. Kale goes from bright to drab faster than you would believe.
- Lacinato holds best. Flatter, darker, chewier. Curly kale is fine and wants five minutes.
- Reheating costs you. The kale dulls on day two. It still tastes good, it just stops being pretty.
Slow Cooker and Instant Pot
Brown the sausage on the stove either way. Skipping that step gives you pale, slightly rubbery coins, and there is no version of the machine that fixes it.
- Slow cooker. Browned sausage, onion, garlic, spices, sweet potato and broth on low for 6 hours or high for 3. Kale in for the last 15 minutes with the lid on.
- Instant Pot. Brown on saute, deglaze with a splash of broth, then 5 minutes at high pressure with a quick release. Kale in on saute for 3 minutes.
- Pour off the fat in both. The rule does not change because the appliance did.
Worth the extra pan? Every single time.
Common Mistakes
I have made all five of these, and four of them more than once.
- Leaving the sausage fat in. A pound of pork sausage renders a lot. You end up with an oil slick, and no amount of seasoning hides it.
- Boiling the potatoes. A hard boil knocks the corners off the cubes and clouds the broth with starch. Simmer gently.
- Adding kale early. Fifteen minutes of simmering turns it olive drab and slimy.
- Under-salting. Broth carries salt differently than a thick stew. Season at the end, taste, then season again.
- Blending it. This is not a pureed sweet potato soup. If you blend it, you have made a different dish.
Variations
- More heat. A full teaspoon of pepper flakes, or hot Italian sausage plus the half teaspoon.
- Creamy version. Stir in the ¼ cup of heavy cream off the heat. You trade the clear broth for richness.
- White beans. A drained can of cannellini in the last five minutes turns it into a fuller meal.
- Andouille and smoked paprika. A half teaspoon of smoked paprika alongside the andouille sends it somewhere else entirely.
- Swiss chard. A fine swap for the kale. It needs only two minutes.
Storage and Freezing
- Fridge. Up to 4 days in a sealed container. The broth thickens slightly as the potato starch relaxes.
- Freezer. Up to 3 months. Sweet potato cubes freeze better than white potato and come back softer but intact.
- Reheat gently. Low heat on the stove. A hard reheat is what actually destroys the cubes, not the freezer.
- Freeze it before the kale. If you know a batch is heading for the freezer, hold the kale back and add it fresh when you reheat.
- Skip the cream for freezing. Dairy separates. Add it to the bowl instead.
Frequently Asked Questions
What kind of sausage is best in kale soup?
Mild Italian pork links, sliced into coins. They already carry fennel and garlic, they brown well, and controlling the heat with pepper flakes separately gives you more range.
Can I use curly kale instead of lacinato?
Yes. Strip the ribs the same way and give it five minutes instead of four.
Why did my sweet potatoes fall apart?
Either the cubes were too small or the pot was boiling. Cut them at three quarters of an inch and keep the heat at a lazy simmer.
Can I make this in a slow cooker or Instant Pot?
Both, and the instructions are up in their own section. Brown the sausage on the stove first either way.
Does it freeze well?
It does, for up to three months. Hold the kale back if you are freezing on purpose and stir it in fresh at reheating.
How do I keep the broth from turning greasy?
Pour off all but a tablespoon of the rendered sausage fat before the onion goes in. If you forget, chill the finished pot and lift the solid fat off the top the next day.
Two small changes and it stops being a greasy pot of drab greens. I promise.
Recipe
Brothy Sausage, Kale and Sweet Potato Soup
Ingredients
For the Soup
- 1 lb Italian pork sausage links sliced into ½ inch coins
- 1 tablespoon olive oil
- 1 yellow onion diced
- 4 cloves garlic minced
- ½ teaspoon red pepper flakes
- 1 teaspoon dried thyme
- 1 ½ lb sweet potatoes peeled, cut into ¾ inch cubes
- 8 cups low sodium chicken broth
- 1 bunch lacinato kale ribs removed, torn into wide ribbons, about 5 cups
- 2 teaspoon apple cider vinegar
- salt and black pepper to taste
- ¼ cup heavy cream optional
Instructions
Brown the Sausage
- Heat the olive oil in a heavy pot over medium high heat. Lay the sausage coins flat in a single layer and leave them undisturbed for 3 to 4 minutes, until browned underneath, then flip and brown the second side. Work in two batches if the pot is crowded. Lift the coins out to a plate.
Build the Base
- Pour off all but about 1 tablespoon of the rendered fat. This is what keeps the finished broth clear rather than greasy.
- Add the onion to the pot and cook for 5 minutes until softened. Stir in the garlic, red pepper flakes and thyme and cook 30 seconds more.
Simmer and Finish
- Add the sweet potato cubes and the chicken broth, and return the browned sausage coins to the pot. Bring to a bare simmer, with lazy bubbles at the edge rather than a rolling boil.
- Simmer for 15 to 18 minutes, until a knife tip slides into a cube with no resistance and the cube still holds its shape.
- Stir in the kale ribbons and cook for exactly 4 minutes, until wilted but still dark green.
- Take the pot off the heat, stir in the apple cider vinegar, and season generously with salt and black pepper. Stir in the heavy cream now if you want a richer bowl.
Notes
- Pour off the fat: all but 1 tablespoon. This is the single step that keeps the broth clear.
- Coins, not crumbles: half inch slices stay visible in the bowl. Chill the links 15 minutes before slicing for clean cuts.
- Bare simmer only: a hard boil knocks the corners off the sweet potato and clouds the broth.
- Four minutes of kale: set a timer. Longer turns it olive drab.
- Season at the end: a thin broth needs more salt than a thick stew.
- Freezing: up to 3 months. Hold back the kale and add it fresh at reheating.
