Do old potatoes taste bad?

In this article, we will discuss whether do old potatoes taste bad, how to differentiate and old potato from a new one, and finally, the best conditions to keep potatoes fresh for a longer period.

Do old potatoes taste bad?

The taste of old potatoes may be somewhat more unpleasant and their nutritional value will not be the same. Old potatoes take on a brownish hue because when their tissues are broken, an enzyme called polyphenol oxidase (PFO) is released, which has the ability to oxidize polyphenols and trigger a series of reactions that end up giving dark compounds (melanoidins).

Here’s how to distinguish an old potato

  • Appearance – When a potato is in bad condition, its size changes and wrinkles, yes, they get smaller and its peel begins to have small wrinkles.
  • Firmness– A rotten potato is watery, when you touch it and press a little you will realize that it is not very hard, if it is watery … do not buy it!
  •  Sprouts – Ok, sprouts may look adorable, but when a potato has these little friends it means it’s been in storage for a long time and it’s best not to eat it.
  •  Color – The color of the potato also tells us many things, you may have noticed that some potatoes have green spots (even French fries), when these spots appear it means that they can cause you a lot of harm because they are “poisoned.”
  •  Smell – We must not underestimate the power of smell, many times (or perhaps always) it tells us if what we have in front of us is in good condition or not, smelling the potatoes is also a great idea to differentiate a good one from a rotten one, the smell deterioration is evident and there is no reason to eat it.

 Potatoes are an important food for humans and accompany thousands of dishes around the world, so it is much better to eat them when they are at their best and avoid illnesses such as fever, headache, dizziness, diarrhea, hallucinations, hypothermia, and (in some cases) death.

How to preserve potatoes?

After being harvested, the potato is still a living organ, which means that metabolic and physiological processes continue to develop in it (respiration, perspiration, etc.), although these take place very slowly due to the dormant state that we talked about before. 

This state, which is regulated by hormones produced by the potato itself, depends on intrinsic factors (variety, genetic factors, etc.) and environmental factors (humidity, temperature, etc.). As you can imagine, what interests us when it comes to storing potatoes is that they remain in this dormant state for as long as possible. 

To do this, what we can do at home is to control the storage conditions (as far as possible, of course), so that if these are favorable, the potato can be kept in good condition for between 7 and 9 months.

What should those conditions be? You may already know that potatoes should be stored in a cool, dark, humid, and relatively ventilated place. But, as is often the case, what is interesting is not the answer itself, but its explanation. So let’s see what these recommendations are for:

Temperature – Ideally, potatoes should be stored at a temperature of between 7ºC and 10ºC, values that are not always easy to achieve in a home … But why that temperature and not another? 

As you can deduce, higher temperature values, such as those usually found in a home (usually between 18ºC and 24ºC), stimulate and accelerate the development of some metabolic and physiological processes, so that:

  •  they cause an increase in perspiration, that is, the cells lose more water. 

In-plant cells, such as those of potatoes, there are large organelles, called vacuoles, in which water is stored which, among other things, maintains a certain internal hydrostatic pressure, giving the turgidity of the cells and increasing their size. 

Thus, as perspiration increases and this water is lost, cells lose turgor and shrink. This results in a series of undesirable changes in the potato, which undergoes weight loss, a reduction in size, acquires a soft and rubbery texture and its skin becomes wrinkled, making it difficult to peel.

  • cause increased respiration. 

This process consists of capturing oxygen used to oxidize certain compounds, such as starch and sugars, to obtain energy. As a result, carbon dioxide is released and there is an increase in temperature and a reduction in weight and size. 

If the respiration rate is too high, there may be sub-boxation problems, that is, a deficient supply of oxygen causes the death of the central cells of the tuber, which become necrotic, giving a black coloration of the inner part of the tuber (black heart ).

  • they favor the formation of sprouts. During the first months after harvest, sprout formation is inhibited by the action of some of the hormones produced by the potato itself. 

Once this time has elapsed, if the environmental conditions are favorable for the development of the tuber (for example, if the temperature is high), it will come out of its dormant state. Sprouts will begin to form that will allow its propagation (processes also regulated by hormones). 

As you can imagine, this is achieved at the cost of consuming the reserve nutrients (mainly water and starch), so if those sprouts develop too much, the potato loses weight, wrinkles, and becomes soft.

In addition to all this that we have just mentioned, you must bear in mind that high temperatures favor the development of organisms that can cause the deterioration of the potato, such as fungi, bacteria, and insects.

Other FAQs about Potatoes which you may be interested in.

How to tell if sweet potatoes are bad?

What to do with sprouting potatoes?

Can you eat sweet potatoes after they’ve sprouted?

How many baby potatoes do you need per person?

The bottom line

Old potatoes may not necessarily taste bad, but they will taste different. We must be careful when consuming potatoes, especially if they have oxidized.  We already know that it is an essential ingredient in our kitchen and an important source of carbohydrates, but we have to know the effects that its misuse can have on our health.

Next time you go grocery shopping, follow our tips when choosing potatoes, and keep in mind that the more fresh the potato is, the better.

If you have any questions or comments on the content, please let us know!