The length of time potatoes last is mostly dependent on the temperature they are stored at. In normal home cupboard conditions the temperature will be roughly 60 fahrenheit / 15 degrees centigrade. At this temperature the potatoes will remain firm for up to two weeks. After this time they will start to soften or begin to grow buds.
How long are potatoes good for
If potatoes are kept at a colder temperature they will last for much longer. Likewise if potatoes are kept in warmer temperatures then the shelf life will be reduced further. My article on how to store potatoes from the garden discusses this topic further
What is the best temperature to store potatoes
The best temperature to store potatoes is 45 fahrenheit /8 degrees centigrade. At this temperature you should expect the potatoes to last up to 6 months from harvest.
Although you can keep potatoes at less than 8 degrees. There are negative impacts on the potato flesh at these temperatures. The potato flesh will turn a dark/black color when fried in oil, for example making chips.
This colour change happens because the starch in the potato turns to sugar. This happens when the potato is exposed to low temperatures to provide quicker access to energy. It is not advisable to store your potatoes below 8 degrees.
How do you know if a potato has gone bad
You will know immediately looking at a potato if it has gone bad or not.
A potato will be bad if it has green skin and/or rotting flesh. Green potatoes are known as “sunburned” or “greening”. If the potato has been exposed to sunlight they will turn green. Solanine is the mild poison the potato produces when it turns green. Find out more about sunburn in my article how to hill up potatoes
Another type of bad potato is one with soft rot or blight. These rotten potatoes will have soft mushy flesh and be dark in colour. It will most likely have a very bad smell.
Can you get sick from eating old potatoes
Not necessarily. The age of the potato is not the issue, the condition of the potato is.
You can have a potato that is 4 months old and was healthy at harvest, stored well and is firm and in good condition. You could also have a potato which is only a week old infected with blight, soft rot or sun damage. All of which would make you sick, if you ate it. It is highly unlikely due to the bad appearance /smell it would have.
A potato that is kept in a cold store in good condition for 3 months. Once brought into a warm house it will be shrivelled up and grown buds 4 inches long. It is now not good to eat.
Can you eat old soft potatoes
This is a better question. Sometimes you can come across a potato which is soft and wrinkly but does not appear to have any diseases or sun damage. Usually these potatoes have begun to produce buds.
You can remove the buds and boil and eat the soft potato but they will not be enjoyable. The answer to this is yes you can eat them, but you shouldn’t. Usually if a potato is firm and has small buds it is fine to eat but if it is soft, wrinkled and has long buds, it is better not to eat it.
Should you keep potatoes in the fridge.
No. As a fridge is usually between 4 to 6 degrees centigrade this is below the recommended 8 degrees. They will keep in the fridge and you could use them for boiling but the flesh will be slightly damaged due to the low temperature and they will not be good for frying
How long do mashed potatoes last in the fridge
What’s the potatoes have been cooked and left to cool they can be stored in the fridge for 3 to 4 days, after this time they should be dumped.
Can you freeze potatoes
You cannot freeze a raw potato. If you do it will thaw out as mush and will be rotten. You can cook potatoes and freeze them for up to 6 months.
How long can you keep a bag of potatoes
Again this is a vague question – if it’s kept in normal room temperature they should last around two weeks. Potatoes keep better in a paper bag than a plastic bag. The plastic bag will encourage the potatoes to sweat. This dampness will speed up the rotting process.
The best place to keep a bag of potatoes is in a paper or cloth bag in a dark room. Ensure good ventilation at 8 degrees.
What happens if you eat a bad potato
It is unlikely that you would eat a bad potato. Unless it was a sunburned one which you missed when putting them into the pot. A rotten potato would never be put into the pot they are mushy and smell terrible.
You could mistakenly put a green potato into the pot. Once you would put a little of it into your mouth the bad taste would make you want to spit it out.
Iif you did eat the green potato you may feel a little unwell and perhaps you would be sick. It is not a major consequence to eat a little of a green potato. It is highly unlikely you would eat a full meal of green potatoes.