I bought a bag of my favourite red potatoes (Desiree) recently. I peeled a few and they looked absolutely fine, but when I started slicing them they all had tiny black "spots" running through the centres. I have never seen this before. Are they okay to cook and eat? Does anyone know what causes the black spots?
"Spotty" potatoes
- Thread starter KatyCooks
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Dawgluver
Chef Extraordinaire
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I would probably dig out the spots. Are they made by insects, or look like something else? It could be mold, bruises, or digging hits, they should be fine for cooking.
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Honestly Dawgluver, the spots are so tiny and there are so many of them, I couldn't dig them out. The weird part is that they are inside the potatoes and not on the outside (so there is no evidence of insects or worms burrowing when you peel them). I don't want to go and buy another bag of the same potatoes and find them exactly the same. I'm doing a fennel and potato gratin at the weekend and I don't want slices of potatoes with loads of black spots in them. (That's an aesthetic consideration rather than a food safety question of course.)
Dawgluver
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Interesting. I've not seen that.
Maybe lots of ground black pepper? (I know, not helpful). Someone here should be along shortly who's seen this.
Maybe lots of ground black pepper? (I know, not helpful). Someone here should be along shortly who's seen this.
Me neither! I have been cooking potatoes for donkeys' years and have never seen this before. (And I thought about fresh ground black pepper too, so no worries!)
I guess I'm just curious to see if anyone has any idea what caused the spots.
Dawgluver
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Wonder if some type of worm/potato maggot got in there before the potato formed, tunneled around, and the tubers grew around them underground. I also wonder if you should take them back to the store and get a different bag, maybe ask to slice one before you buy the bag.
Did you check your knife for rust?
Did you check your knife for rust?
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It's a major UK supermarket. I guess I could take the remaining bag back and cut a potato open in front of them (except I might get arrested if I took a knife out in front of the customer service person!)
Oh, and my knives are old and trusty! Definitely not rusty!
Cooking Goddess
Chef Extraordinaire
I've had potatoes with running lines of black spots, almost looking like a very short dashed line. It's maybe 1/4 inch from the surface, running in a curve following the shape of the potato. I've always used the potatoes just like that and with no ill effect. I've always figured it was just some sort of "growth spurt" while the potato was growing larger, but not quite a growth ring. Anyway, I've cooked them and we've eaten them and we're all still alive. Use more pepper, like you said.
Addie
Chef Extraordinaire
I say use them, but take a couple of them back to the store and ask to speak to the produce manager. Cut it open in front of him. He would surely want to know and be able to notify the supplier or farmer of this problem. Check the bag to make sure they are not imported. If they are you may want to consider changing brands. 
I'll bet 80% of the potatoes I cut into have larger black spots on them. I figured they were bruises, but it isn't like the blackened area is soft, so beats me.
The funny thing is I never run into them when I bake a whole potato. That leads me to think the black area turns white as it cooks, because you would certainly think one would show up once in a while. I always cut them out if I see them, so I'm not sure if the black area really does turn white if I was boiling or frying the spuds.
The funny thing is I never run into them when I bake a whole potato. That leads me to think the black area turns white as it cooks, because you would certainly think one would show up once in a while. I always cut them out if I see them, so I'm not sure if the black area really does turn white if I was boiling or frying the spuds.
Oldvine
Sous Chef
It sounds like some kind of blight probably caused by growing conditions... too much water, too little water, too hot, too cold. If it's just a small bag, I would toss them or take them back if they were spendy in price. I would buy the replacement bag at a different store to avoid the same harvest lot.
Dawgluver
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I think you have it, Oldvine.
Cooking Goddess
Chef Extraordinaire
Now that you've mentioned this I have never noticed the spots when I go to mash them. Maybe they are gone, could be I just don't notice. Now you have me thinking that I hope I run across a spud or two with these marks.
Katy, there is one thing you can be sure of - if the potato is spoiled you WILL notice! Did they have an "off" odor, or did they smell like a regular, fresh-cut potato? The smell test is usually spot-on.
I've had potatoes with running lines of black spots, almost looking like a very short dashed line. It's maybe 1/4 inch from the surface, running in a curve following the shape of the potato. I've always used the potatoes just like that and with no ill effect. I've always figured it was just some sort of "growth spurt" while the potato was growing larger, but not quite a growth ring. Anyway, I've cooked them and we've eaten them and we're all still alive. Use more pepper, like you said.
Well, it sounds very similar - though my spots are less neatly arranged than yours, but since you are still alive Cooking Goddess, I shall take the plunge (with extra pepper as suggested!)
No, the spuds are absolutely fresh. As I mentioned, when you peel them, they look pristine - not a mark on them. It's only when you cut them in half or slice them that you see all the tiny dots in the middle of each potato. (So far it has been every potato I have picked - and luckily it was quite a small bag.) I think I will boil one, uncut and then see if the spots are still there after they are cooked. (Just as a little experiment.)
I think Oldvine's comment about growing conditions sounds like the most likely reason for them. It has been a very odd year weather-wise in the UK.
Aunt Bea
Master Chef
Does it look like this?
This potato has a potato blight, similar to the one in Ireland years ago. The blight has been popping up in the US this year.
This potato has a potato blight, similar to the one in Ireland years ago. The blight has been popping up in the US this year.
I don't think this is what you have, but it is amazing the things you find when you do a google search. I do think I have seen some potatoes like these.
https://www.google.com/search?q=fus...9ONStyAHZ74CABg&ved=0CDIQsAQ&biw=1024&bih=644
https://www.google.com/search?q=fus...9ONStyAHZ74CABg&ved=0CDIQsAQ&biw=1024&bih=644
If you are only concerned about esthetics, why not boil one potato and see if the spots vanish. Like Pac, I don't see them in baked potatoes. I always cut off anything the wrong colour. If the spots don't vanish, do bring the bag back to the store.
