How To Fix Undercooked Potatoes In Different Recipes

Potatoes are a handy and nutritious staple in most homes. Sometimes, your trusty recipe goes wrong, and your potatoes are raw, lumpy, or unevenly cooked. Why don’t potatoes always soften? And how do you fix potatoes when they’re undercooked?

It is possible to fix undercooked potatoes. Try cooking them for longer or use the microwave. Fix undercooked potatoes in soups and stews by cooking them separately. Rescue mashed potatoes by gently reheating them with milk. Chop potatoes evenly and cook gently, whether simmering or baking.

We’ve all ended up with undercooked potatoes. Luckily, this doesn’t spell disaster as you can usually rescue your meal. Let’s look at how to fix undercooked potatoes in a stew, soup, mash, and in the oven and avoid making potato mistakes in the future.

There are three main reasons that potatoes end up undercooked.

Reasons Your Potatoes Are Undercooked

Reason 1: Not Cooked Long Enough

The simplest explanation for undercooked potatoes is that you haven’t cooked them long enough, especially larger potatoes. 

Even baby potatoes or diced potatoes will take at least 15 minutes to cook in boiling water, while larger potatoes need 20-30 minutes to cook through. Baked or roast potatoes take even longer to cook – up to an hour.

Reason 2: Cooked Unevenly

Sometimes you find your potatoes are soft on the outside, but when you cut them open or try to mash them, they are still hard and undercooked at the center.

There are a couple of causes of potatoes cooking unevenly: 

  • Your pot is too small, so the potatoes don’t get enough consistent heat to cook evenly.
  • Your potatoes are in different sized pieces, cooking through at different rates.
  • You put your potatoes into already boiling water and then cook them vigorously. The outside of the potato cooks, while the interior remains raw. 

Avoid uneven cooking by chopping your potatoes into evenly sized pieces (1-2 inch chunks), starting the cooking process in cold, salted water, and cooking the potatoes at a simmer or gentle boil.

Reason 3: The Dish Is Too Acidic

If you’re making a stew, soup, or casserole that contains acids (from lemon juice, vinegar, sauerkraut, tomatoes, or wine, for instance), you may find that your potatoes just won’t soften.

The reason is that potatoes contain pectin and cellulose as part of their cell walls. These substances require cooking to break down, soften, and release the starch that makes potatoes delicious and soft.

Acids prevent pectin and cellulose from breaking down, so your potato remains hard, no matter how long you cook it.

How To Fix Undercooked Potatoes In Stew

Having chunks of undercooked potato can ruin a hearty stew. Potatoes usually end up undercooked if your stew contains acidic ingredients, which prevent the potato from breaking down. Potentially the chunks were also too large or uneven.

To fix undercooked potatoes in a stew, try the following:

  • Add ¼- ½ teaspoon of baking soda to neutralize some of the acids in the dish. Your potatoes should soften given time – try another 15 minutes.
  • Simmer the stew for longer until cooked. If you don’t want other ingredients to soften too much, remove the potatoes from the stew, rinse them, and boil or microwave them separately until soft.

Next time you want to make a stew that contains potatoes, consider precooking the potatoes or adding acidic ingredients at the end of the cooking time. I also wrote a whole article on avoiding mushy potatoes in stew.

How To Fix Undercooked Potatoes In Soup

We usually add potatoes in soup as a thickener, so undercooked potatoes are a disaster. As with stew, the main culprit for undercooked potatoes is acid in the other ingredients, usually tomatoes. Another possibility is that your potato pieces are too large and cook slower than the rest of the soup.

To fix undercooked potatoes in soup, try the following:

  • Simmer the soup for longer until cooked. If you don’t want other ingredients to soften too much, remove the potatoes from the soup, rinse them, and boil or microwave them separately until soft. You can simmer soup for too long.
  • Add some salt to the soup. Salt helps to break down the pectin preventing the potato from softening.

To ensure that you have soft, luscious potatoes in your next soup, try cutting the potatoes into small, uniform chunks to cook more quickly. Precooking the potatoes also helps.

How To Fix Undercooked Mashed Potatoes

The reason for lumpy mash is usually potatoes that are unevenly cooked which leaves some soft parts of potatoes and harder other parts. How can you fix undercooked mashed potatoes?

  • If you’ve already started mashing the potatoes, don’t panic. Return the lumpy potatoes to the pan and add a dash of full-fat milk, half-and-half, or cream to the potatoes. Cook gently over low heat, mashing now and again until the lumps break down. Add more cream or butter if necessary.
  • If the lumps are small, put the potatoes through a potato ricer or metal sieve to gently break them up. This ensures the smoothest mash.

If you are regularly making lumpy mashed potatoes, you need to check your cooking method:

  • Cut the potatoes into small, uniform chunks to cook evenly.
  • Start the potatoes off in a pot of cold, salted water. The salt allows the potato to boil at a hotter temperature, releasing and cooking the starch more thoroughly. This process means creamier, smoother mashed potatoes.
  • Cook the potatoes low and slow – keep them at a simmer, not a vigorous boil. 
  • Check that the potatoes are done by inserting a fork deep into the potato. If the fork slips in easily, your potatoes are ready to be mashed.

How To Fix Undercooked Baked Potatoes

A fluffy, piping-hot baked potato is the best kind of comfort food. But when potatoes turn out undercooked, what can you do?

  • Wrap the potatoes in aluminum foil and return them to the oven if you’ve got time. Large potatoes can take over an hour to bake.
  • If you’re in a hurry, prick the potatoes with a fork, place them on a plate, and microwave them for three minutes on each side.

To cook baked potatoes properly, keep them low and slow. Bake potatoes at 300⁰F (150⁰C) for an hour to ninety minutes. A hot oven will cook the outside of the potato but leave the inside raw. I wrote more about this in my post can you overbake a potato?

How To Fix Undercooked Boiled Potatoes

Boiling potatoes is a go-to method of cooking. If your boiled potatoes turn out unevenly cooked or undercooked, you can still rescue them:

  • Whenever possible, cook the potatoes for longer at a low simmer.
  • If you’ve already drained the potatoes, chop them into smaller pieces and return them to the stove in fresh, salted water.
  • In a hurry? Pop the potatoes in the microwave to cook quickly.

If you’re boiling potatoes unsuccessfully, try cutting the potatoes into small, uniform chunks to cook evenly. Start the potatoes off in a pot of cold, salted water and cook them at a simmer. Should you peel your potatoes before boiling? I answer that in a previous post.

If you are making potato salad then check out my post on fixing undercooked potato salad.

How To Fix Undercooked Roasted Potatoes

There’s nothing like fork-tender roast potatoes with a crisp edge and fluffy interior. If you end up with undercooked roasted potatoes, here are some tips:

  • If the meat is cooked but the potatoes aren’t, leave the potatoes in a hot oven (400F/200C+) while the meat rests. You can happily carve the roast while the potatoes cook for longer – don’t worry about overcooking them as they just get crispier which is a good thing.
  • Microwaving the potatoes will cook them through, but you will lose the crunchy exterior.

To make sure you produce perfect roasted potatoes every time, cut evenly and boil for 15 minutes first to partially cook. Roast the potatoes in the center rack of the oven with hot oil, and flip them a few times to ensure the potatoes cook evenly.


Hopefully, now you know how to fix your undercooked potatoes. Usually caused by cooking too little, too vigorously, in a small pot, or with acids, undercooked potatoes don’t have to be a cooking nightmare.

You can fix undercooked potatoes in soup, stew, or mash, and even roasted, boiled, and baked potatoes quickly and easily. You can also prevent undercooking potatoes in the future with the tips in this article – I hope they were of help.

Have any questions? Ask me in the comment section below and I’ll get back to you.

Tom Hambly

Tom Hambly is the founder of Boss The Kitchen. With a background in cooking and building websites, he enjoys running this site to help other cooks improve. About Tom Hambly.

Leave a Reply

Your email address will not be published. Required fields are marked *

Recent Posts