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I've stored some of my potatoes but the light has got in and quite a few have gone green. Can I get the green to go or will I have to throw them away? ( this is for eating )

When potatoes are exposed to either artificial or natural light, they can develop a green colour due to chemical changes. These may make those green bits of the potato unsuitable for consumption (toxic) but they can be avoided by simply cutting them out.

Once they're green they're green Im afraid and poisonous to eat, but Im not sure if they could be saved for seed for next year?

Hopefully someone will know as I would be interested to find that out too ;)

 Hi ! I came across a small bag of seed pots that I,d forgot about about four weeks ago ......all green and sprouting little shoots...so I put them all in a tub and covered them with a bit of compost and they are growing well and strong and I have repeated the covering them up with more compost several times now ....hoping to have new pots for New Year.     I am gutted to hear they may now be poisonous !    I would,ve thought any new pots developing off the seeds would be just normal....am I wrong ?
                  Rohaise X

No Rohaise, it doesn't matter that the seed potatoes were green, the new potatoes will be just fine as long as you keep them earthed up whilst growing. I found that most of my seed went green when laid out for chitting earlier this year.


Star, if the green is not too deep into the potato, you can get rid of it by peeling deeply (presuming the spuds are big enough to peel that is), and they should be fine. Just peel down until you get to the white/creamy flesh underneath the green.

Agreed quiz, I was doing the presuming bit thinking they may have been small spuds or completely green, I really must take more time with my postings :-[

I do peel off the green as you suggested if they are big enough. Im sorry Hazelb and Rohaise if I misled you.....

Big note to self.........I must take more time with my posts ;)

I mentioned to my doctor daughter a few days ago that my generation believed that eating green potaoes contributed to Spina bifida in their babies, and she laughed at me.

Well, we do our best on the information given to us at the time. OK, they are poisonous, but I now don't know exactly what the probem is if you do eat them (apart from a bitter taste).

Solanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhoea, vomiting, stomach cramps, burning of the throat, headaches and dizziness. Hallucinations, loss of sensation, and paralysis, fever, jaundice, dilated pupils and hypothermia have been reported in more severe cases.

In large quantities, solanine poisoning can cause death. One study suggests that doses of 2 to 5 mg per kilogram of body weight can cause toxic symptoms, and doses of 3 to 6 mg per kilogram of body weight can be fatal.

Blimey grotbag, thats completely different to what I first thought and much more gruesome.

I was under the impression they contained chlorophyll, which could also (obviously) cause stillbirths.

Thanks for posting, I may never remember everything in your post but its nice to have the right answer :D

Most green tissue from this plant family is poisonous, with the obvious exception of green tomatoes. That being said, I wonder how many green spuds you'd have to eat to get a dangerous dose; how much solanine would there be in one?

Judging by grotbags post an 80 kilo person would need about 40mg to be fatal. So I guess a whole med green potato or even a small one wouldnt be advised. (my maths is cr*p BTW)

But with this knowledge I wouldn't personally eat ANY green part, not that I ate it before

QuoteSolanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhoea, vomiting, stomach cramps, burning of the throat, headaches and dizziness. Hallucinations, loss of sensation, and paralysis, fever, jaundice, dilated pupils and hypothermia

I'm absolutely positive something is missing.

Quote80 kilo person would need about 40mg to be fatal

5 * 80 = 400. Presumably that is raw but how much of the toxicity would be lost in the cooking?

Quote from: Eristic on October 17, 2007, 07:13:13

QuoteSolanine poisoning is primarily displayed by gastrointestinal and neurological disorders. Symptoms include nausea, diarrhoea, vomiting, stomach cramps, burning of the throat, headaches and dizziness. Hallucinations, loss of sensation, and paralysis, fever, jaundice, dilated pupils and hypothermia

I'm absolutely positive something is missing.

Quote80 kilo person would need about 40mg to be fatal

5 * 80 = 400. Presumably that is raw but how much of the toxicity would be lost in the cooking?

I only wanted to quote your last sentence, cant do it.

:-[ :-[ yep Im rubbish at maths :-[ :-[

Unfortunately the green colour is just the indicator that the potato has been exposed to light. The actual poison is colourless and develops after exposure to light. Cutting off the green doesn't help as the poison will still be there. The level of poison in a potato varies with variety in some varieties the amount of poison that develops when exposed to light can be very high. In the new mainstream varieties breeding may have reduced the poison content but unfortunately I haven't been able to find a list yet that tells you which varieties produce the most poison. I would however be very careful of old heirloom varieties. Personally I throw all my green potatoes away. My local waitrose doesn't seem bothered twice this week i've looked at their potatoes and they've all been green.....really green and on sale.

Oh I forgot.....the answer to the question is No you can't change them back. Sorry.

there's a theory that you might be able to improve prison life by stopping feeding prisoners potatoes. The quality of potato used to make stuff for prisons, and other institutions i suppose, is so shockingly bad, that they're all going round in a state of mild solanine poisoning, with all kind of bad behavioural results
Just one of those QI ideas, like the one about bringing peace to the Middle East by getting everyone to eat lots of Marmite

all the potato family (solanums) are poisonous and this includes tomatoes and aubergines - could write a thesis on this but enough to say that many humans have managed to acclimatise to the 'poison' but for those who haven't or could not they tend to display an allergic reaction  as an indicator that they are eating a basically poisonous plant - so whatever colour they are we might all be more healthy for not eating them but most of us are not likely to stop  :)

Yes If you have Rheumatoid arthritis it can help if you don't consume any members of the Solanaceae family. My sister followed this advice and claimed it helped however she wasn't happy with me when I suggested it would work even better then if she stopped smoking! (Tobacco is in the same family). I haven't tried it myself yet being pretty much addicted to most of the edible Solanums (not Tobacco!).   

BLIMEY! It's enough to put you off chips innit  ::)