I’ve never seen potatoes like this before! I threw them out. What’s this black stuff?

If you cut open a potato and see a dark black or brown mark in the center, it can look shocking. Many people think the potato is rotten, moldy, or unsafe. But in many cases, this dark area is caused by an internal growth defect, not an insect, dirt, or disease.

The condition is commonly called “hollow heart” or “brown center” when the inside has a hollow space or brown discoloration. If the center is very dark or black, it may also be described as “blackheart,” another internal potato disorder. Hollow heart is often linked to uneven growing conditions, especially when potatoes grow too fast after stress from too much water, dry periods, or temperature changes.

Important fact: This problem usually starts inside the potato, so the outside may look completely normal.

What causes it?

Potatoes can develop these marks when the plant is stressed while growing. Sudden changes in soil moisture, heavy rain, heat, cold, or uneven growth can affect the inside of the tuber. In some cases, blackheart can also happen when potatoes do not get enough oxygen, especially during storage, transport, flooding, or temperature extremes.

Is it safe to eat?

In many cases, a potato with hollow heart is not dangerous, and the affected part can be cut away if the rest of the potato is firm, white, and smells normal. However, if the potato smells bad, feels soft, looks moldy, is slimy, or has large black areas through many slices, throwing it away is the safest choice.

What is the “use” of potatoes?

Potatoes are a common starchy vegetable used in American kitchens for many foods, including baked potatoes, mashed potatoes, fries, hash browns, soups, stews, and roasted side dishes. They provide carbohydrates for energy and also contain nutrients such as potassium, vitamin C, vitamin B6, and fiber, especially when eaten with the skin.

Does the black part have any use?

No. The black or brown center itself has no special use. It is simply damaged internal tissue. For cooking, people usually cut out the dark area and use only the clean, firm potato flesh.

Bottom line: The black marks inside these potatoes were most likely caused by an internal potato disorder such as hollow heart, brown center, or blackheart. It is usually related to growing or storage stress, not something crawling inside the potato. Still, if the potato looks or smells unpleasant, throwing it out is a reasonable decision.