It can happen with any type of potato, Yukon gold, red, white, and so on.
You cook them for longer than the recipe said too, and yet they just won’t soften.
In general, there are a few reasons this happens. I’ll go over them and how to prevent this in the future, as well as how to try and salvage potatoes if you find yourself with undercooked potatoes.
Table of Contents
2 Reasons Your Potatoes Won’t Soften
There are primarily 2 main reasons why potatoes won’t soften, assuming they’re not rotten in the first place.
Note that being at a high altitude will slow down cooking, but they should soften after a longer time.
Acid Prevents Potatoes From Softening
Both pectin and cellulose are main components of a potato’s cell walls.
While some ingredients like salt can help dissolve pectin, acid limits the breakdown of both pectin and cellulose. If the cell walls cannot break down, the potato won’t soften much.
So if you’re adding potatoes to stews and soups that contain acidic ingredients like lemon juice or tomatoes, they’ll barely cook no matter how long you cook the dish for. Any ingredient that is vinegar-based or fermented like sauerkraut will have the same effect.
Cooked in Vigorous Boiling Water
If your potatoes are soft on the outside but still undercooked in the middle, the likely cause was cooking them at too vigorous of a boil. The potatoes may appear soft on the outside, which cooks at a fast rate, while the inside is not done cooking.
Potatoes should be boiled at a simmer (i.e. a very gentle boil). If you’re going to cook them at a vigorous boil to save time, at least cut them up into small pieces beforehand.
How to Prevent Potatoes From Not Being Able to Soften
There are a few things you can do to prevent this issue in the future:
- Pre-cook the potatoes if you’re planning to cook them in an acidic dish (i.e. contains lemon, tomatoes, vinegar)
- Add any acids towards the end of a dish
- Cut your potatoes to a smaller (but uniform) size
- Cook them at a simmer (a temperature too low won’t soften starch in a potato, while too high can result in an undercooked middle)
Is it Dangerous to Eat a Slightly Raw or Undercooked Potato?
A raw potato is edible, it’s just not going to taste good. As long as the potatoes have been washed and aren’t rotten, it should be safe.
However, they will be harder to digest, which will often lead to some stomach discomfort.
How to Fix Potatoes That Won’t Soften
It’s hard to completely “fix” potatoes that are at this stage, but you can usually at least salvage them.
If the potatoes are slightly soft, but not soft enough, simply cook them longer. If you don’t have time to wait, prick a couple holes in the potatoes with a fork and put them in the microwave for 2-4 minutes.
If the potatoes won’t cook in an acidic dish, it’s pretty impossible to fix completely because you can’t remove the acid. Adding in 1/4-1/2 teaspoons of baking soda can neutralize some of the acidic environment to encourage softening (a similar thing can help when beans won’t soften), but it’s not a miracle fix.
If you’re cooking whole potatoes in plain water, consider draining away the current starch water and letting them cool down a bit. Then cut them into smaller pieces and cook again.