Why do my red skin potatoes have purple patches under the skin?
by Nicole (Windsor, Ontario)
I have these red skin potatoes and they have purple patches under the skin why?
Hi Nicole, Finding purple “patches” under the skin of red potatoes can be as surprising as finding green patches. However, there is a difference between purple patches and deep red patches.
Red or purple, that means that those colored areas should be removed. Of course, it all depends if those areas are small or not.
When you mention the word “patches”, it probably means that those areas are not that small at all.
If the purple patches cover almost one half of the potato, I would cut off that area and check the other half to see if it has a normal color. If the other half looks ok and doesn’t smell bad, then that other half it’s ok and you can cook it.
Red potatoes are not the only ones with some color under the skin. Russet potatoes may have purple spots; sometimes people called them “purple veins”, and, of course, you should remove them or discard the potato immediately.
Back to the “color” issue, some potato varieties tend to develop the potato variety is red, it would be very common to find some reddish flesh or red “veins”.
When that’s the case, there is nothing wrong with the potatoes; if fact, you could cook and eat the potato and it’s fine.
But, if the potato it’s red and the color under the skin is purple, that’s not common. The purple color could be because of a potato disease caused by a fungus, specially if you notice that the purple area covers almost the entire potato.
When the cause is a fungus, it usually happens at harvest or during the storage process.
It’s difficult to discard all the “bad” potatoes because the process is automated. Sometimes, machinery can spread the disease to other potatoes, so it’s difficult to keep the tubers free of any kind of diseases.
In addition to this, as long as the potato looks good on the outside, we know that the only way to find out if the potato is ok or not is by cutting them. It can happen with any other vegetable, not only to potatoes.
Fortunately, the solution is to cut off the bad areas or discard the potato. And cook and enjoy the rest of the potatoes!