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Why Your Potato Soup Came Out Gritty

You made potato soup and you did everything that the recipe said. For some reason, it turned out gritty—as if you had made Quaker grits or breakfast porridge.

The kind that feels overly dry and somewhat grainy when you eat it. Or that, when you turn over your spoon and let it run off, it leaves flakes on the metal.

What went wrong?

As regular readers of Home Cook World know, troubleshooting cooking mistakes is one of my favorite things to do. I guess that’s because I make them myself so often!

So let’s see about this one.

Potato soup can come out gritty because you used floury instead of waxy potatoes. Other reasons are not peeling the spuds, overcooking them, or curdling the dairy products in your soup by adding them in over excessively high heat.

The potato variety that you choose for your soup and literally make it or break it.

Here’s the rundown.

Which Potatoes Are Best for Soup?

In general, grocery stores carry two kinds of potato varieties: floury and waxy. The difference between them comes from the amounts of moisture and starches that they contain.

Floury potatoes contain little water and plenty of starch. This is why they’re dry and fluffy, making them perfect for frying, pureeing, and baking—less so for preparing soup.

Waxy potatoes have fewer starches and plenty of water. They’re crisp, moist, coming out creamy and holding on to their shape exceptionally well when cooked. That’s why they are so suitable for boiling and steaming.

The best potatoes for potato soup are Yukon Golds, Fingerlings, and Red potatoes.

Avoid using Idahos or Russets; their low level of moisture and high level of starch turn them into an excellent choice for frying and baking but a poor one for preparing soup.

Peel the Potatoes Carefully Before Boiling Them

Unpeeled spuds are the most apparent cause of them all, but it can happen.

Especially if you used a thin-skin potato variety, like Yukon golds, and didn’t pay much attention to the process because you were tired, distracted, or in a hurry.

The fix for this mistake is easy to understand but hard to master: I call it “mindful cooking.”

When I cook, I try to be as attentive as possible to the things that I’m doing. While it’s tempting to catch up on my favorite cooking shows or podcasts, I’ve also seen that it’s detrimental to the quality of my food since it becomes easy to forget a step or two of a recipe.

Also, I find it more practical to remove the peel before boiling the potatoes (at least when making soup). Otherwise, they turn soft, and leaving tiny bits and pieces of skin on them that can make my soup gritty is all too easy.

Boil the Potatoes Till They Turn Creamy

Undercooking is another common cause of gritty potato soup.

Exactly how long it takes to boil potatoes depends on too many factors, like the variety you chose and each spud’s size, to have a general rule of thumb. Instead, learn how to tell when the potatoes are done.

Still, if you’re looking for a rough estimate of the cooking time, that’s typically 10 minutes for sliced potatoes (from the moment you’ve brought the water to a boil) and 20 minutes for whole potatoes.

When boiling potatoes, choose similarly-sized spuds or cut down the bigger ones into smaller-sized pieces. Add the potatoes to the pot while the water is still cold, and season the water with a generous pinch of salt to bring out their aroma and flavor as they cook.

Set the heat to high to bring the water to a boil quickly, then reduce to medium and let the spuds simmer. Cook until you can easily pierce them with a fork or pairing knife, and it slides smoothly all the way to the center.

Keep the Cheese or Cream From Curdling

If the recipe called for adding a dairy product to your potato soup—like shredded cheddar cheese or sour cream—it could have curdled if you did so at excessively high heat.

Dairy products contain coiled-up proteins. When you heat them, they uncoil and bind to one another, separating from the liquids and turning into firm and rubbery curdles (basically, the same thing that happens inside an egg when you boil it).

If you add shredded cheese, sour cream, or milk to your potato soup while it’s still boiling, the high heat (water boils at a temperature of 212°F) will cause the proteins contained in it to curdle.

To prevent this from happening, add dairy products to your potato soup only after you’re done boiling the potatoes. Take the soup off the heat and whisk the cheese, cream, or milk in. Use the residual heat of the liquid to bring it all together.

The Bottom Line

No more gritty and grainy soup! By choosing the right kind of potatoes and applying the correct cooking techniques, your potato soup will come out creamy every single time.

Remember to use Yukon Golds and Red potatoes, make sure they’re well-peeled, cook the buds till you can easily pierce through them with a fork or knife, and add cheese or cream after you’ve taken the pot off the heat.

How did my tips and tricks work out for you? Do you have any cooking hacks of your own that you’d like to share with the rest of this post’s readers and me?

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Written by

Jim is the former editor of Home Cook World. He is a career food writer who's been cooking and baking at home ever since he could see over the counter and put a chair by the stove.