Are soft potatoes still good to eat?

Answer 1

I cannot find any specific reference to this, but I am a biological scientist and ex farmer, so perhaps my answer to this will carry a bit of weight.

Potatoes go soft for various reasons, and their safety depends on the cause.

1/ the spud is infected with a blight that makes a spud soft even at harvest. Discard, as these can be quite toxic. Commercially bought spuds should not contain any like this, but home grown ones might get blight.

2/ "glassy" spud. This too is an infection. The spud is not so much soft, as has a translucent appearance and is hard even after cooking. It is not toxic, but the spud tastes unpleasant and has a nasty texture. Not worth eating unless you're starving.

3/ The potato has died in storage and is decaying. This should be fairly obvious. Like any dead thing, it will rot, and the first stage could well be softening, before dissolving into a puddle of foul smelling slime.

But say that hasn't happened yet, and the spud is dead, a bit soft, but there are no other signs, like mold, bad smell or obvious bacterial colonies on the surface.

If you cut it open and find black spots inside, then it is definitely infected and should be discarded. If not, it is probably safe, but it is still a bit like eating fresh road kill.....

It's probably a bad idea to eat a dead spud, even if as yet it isn't showing any obvious signs of decay. I just wouldn't. Added: I'm another biologist, and I think dead potato's are fine to be eaten. The question is whether rot has set in or not. If they aren't smelly and have no green or black spots then it should be fine. However it may have a diminished taste, texture or nutrient value.

4. The spud is sprouting. When this happens, the growing point takes nutrient from the body of the spud, making it soft. Now, provided it is sprouting in the dark, and you cut out the sprouts, the rest of the spud, admittedly soft, is quite harmless.

However, if the spud is sprouting in the light, it will certainly also be greening, and all green parts are poisonous! Again though, provided you cut away all green parts and skin, what's left is OK, BUT, again if the whole spud has turned green, the toxin will have spread deep into the flesh, so again it should definitely be discarded.

5/ The spud has been kept in the fridge. Bad idea. Spuds are alive, and should be stored at room temperature in the dark. Being kept at four degrees Celsius will in due course kill a spud just like it'd kill you.

However the refrigeration also inhibits decay. In fact a refrigerated spud may well still be alive, but moribund, and dehydrated, which will make it soft. This spud is quite safe to eat.

On the other hand, if you take your refrigerated soft spud and find it has black spots, or particularly black veins on the inside, it is not only dead, but is also infected with fungus. In my experience, small amounts of this are harmless, but *all* fungi should be treated with deep suspicion.

And though some fungi are harmless, most at least taste bad, others will make you nauseous, in some cases even cause actual food poisoning, an allergic reaction, and in a worst case scenario, kill you outright (Clostridium botulinus in particular.)

So, if your spuds have been kept in the fridge, have gone soft, don't smell funny, and have only superficial blemishes, I'd say if you're desperate, peel 'em, boil 'em and eat 'em.

They'll taste OK, and even firm up in the cooking, especially if you make fries from them. So, - you just won't know the difference. But all other instances of soft spuds except greening after removing all green parts, should be studiously avoided.