At what temperature does potatoes freeze?

Potatoes are one of the most popular products that our compatriots grow in their private plots. In order to eat root crops from your own garden all winter, it is important to create the right conditions for its storage. To do this, you need to know how the potato reacts to temperature.

For long-term storage, a temperature of + 2 ° C to + 4 ° C is recommended. With it, all physiological and biochemical processes stop in the tubers, the potato seems to go into hibernation, due to which all its properties, including taste, remain unchanged. A short-term temperature change of 1-2 ° C is allowed. But if the temperature is much lower or higher than the optimum, decomposition processes begin in the tubers, which lead to spoilage.

Potatoes react to temperature in the following way.

• When the temperature rises from + 4 ° C to + 8 ° C metabolic processes in tubers resume, they wake up and begin to sprout. For a couple of days, of course, nothing terrible will happen, but further, as the sprouts germinate, the harmful substance solanine will accumulate in the vegetable.

• For a short time (from several days to a week) portions of potatoes to be used for cooking can be stored at 7-10 ° C. But the entire crop, of course, should not be stored at this temperature - it will begin to germinate and then rot

• When kept at room temperature for a long time, potatoes begin to decompose. First, the starch contained in it breaks down to form sugars. Further, oxidation processes are activated in the product, leading to the formation of carbon dioxide and water. In a dry room, gases quickly evaporate, and the remaining solid part of the potato dries up and "mummifies", becoming like a large hard raisin. If the humidity is high, the potatoes become slippery, moldy and rot.

• The standard freezing point for potatoes is -1.7 ° C (frost-resistant varieties do not freeze and even withstand temperatures down to -3 ° C), but some processes begin already at 0 °. The liquid in the tuber at this temperature begins to turn into ice crystals, and the cells and tissues die off, which causes the vegetable to decompose. The course of the processes depends on how strong and long-term the effect of the cold was. Short-term exposure to relatively low subzero temperatures simply freezes the potatoes. It will acquire a specific sweetish taste, but still remain edible. Sometimes it even retains the ability to reproduce and grow, and it can be planted in the ground in the spring. If the effect of cold was strong or prolonged, the decomposition processes become irreversible, living tissues completely die. Such a product becomes unsuitable for any use, and after thawing it will rot.

You can understand whether the potatoes were badly damaged by frostbite by the color change.

• If, after thawing (within 1-2 hours in a warm room), the tuber in the section retains its usual white color, everything is in order, the crop can be saved.

• With severe freezing, the affected areas become dark - brown or black. They need to be cut off.

• If the potatoes have completely darkened, it remains, unfortunately, only to throw them away.

It is important to remember that the optimal temperature is only one of the factors for the long-term preservation of potatoes. And also it is necessary to provide:

• air humidity - from 80 to 95% so that the vegetable does not begin to dry out or rot;

• good ventilation;

• protection from light so that the tubers do not turn green.

In our climate, potatoes during storage suffer from cold much more often than from overheating. It is because of the impact of negative temperatures that most often it is not possible to preserve the harvest. There are several scenarios in which this happens:

• the potatoes are frozen while still in the garden;

• the crop freezes if it is dug up, but not placed in storage on time;

• in case of improper, unprotected storage - on an open loggia, balcony, terrace;

• in a pit or storage room if the temperature drops dramatically.

Let's analyze each option in more detail. Potatoes can freeze on a bed only if the surrounding soil layer freezes to -1.7 ...- 3 degrees. This happens only with prolonged establishment of day and night temperatures below zero, for the middle band - in November-December.

With small autumn or unexpected summer frosts, the soil does not have time to cool down to such a temperature - it cools down much more slowly than air, and retains heat for a long time, protecting the roots like a blanket. With the first frost, the temperature of the upper layers of the soil can be 5-10 ° C higher than the air. Moreover, soft, loose soil retains heat best and for the longest time, and mulching creates additional protection from the cold.

Still, the optimum temperature for digging out and drying potatoes is 12 to 18 ° C. Then to prepare potatoes for wintering, it is better to lower the temperature gradually (optimally - by 0.5 ° C per day), so that the vegetable gradually “falls asleep”. In case of sudden changes, as well as if, when digging outside, less than + 5 ° C, the potatoes are exposed to severe stress, which can adversely affect its keeping quality.

Much more often than in the ground, tubers freeze if stored improperly. Here you need to know the following.

• On an open unglazed balcony, in the ground part of an unheated garage or shed, potatoes that are stored in bulk or in cloth bags may freeze even when the air temperature is less than 0 ° C. Therefore, such storage facilities are suitable only as temporary storage facilities in warm autumn.

• In a city apartment, the best storage place will be a glazed loggia with additional insulation. It is better to place vegetables on it not in bags, but in boxes to ensure good ventilation and reduce the risk of mold and rot. The boxes should also be insulated with foam or cardboard, additionally covered with quilted jackets. This will protect the vegetable from freezing even if the outside temperature drops to -7 ° C. With a further decrease in temperature, there is a risk that the potatoes on the loggia will freeze.

• Another budget way to store potatoes is in an earthen hole in the garden. Potatoes buried in such a hole for the winter can survive until spring, but provided that the vegetables are below the freezing level of the soil. Therefore, the pit should be quite deep, about 1.5-2 m, and properly insulated from below and on the sides, and on top there should be a layer of straw and leaves 35-40 cm thick.But there are still risks that the potatoes will suffer from frost, after all, the depth of soil freezing can vary greatly in different years, and when the snow melts, there is a danger of flooding by groundwater.

• The optimal way of wintering potatoes is in a specially equipped cellar or basement of a house or garage. Such a room should have a layer of thermal insulation corresponding to climatic conditions, good ventilation, but at the same time cold air from the street should not enter the compartment with vegetables. Therefore, a cellar is erected above the cellar, in the garage or house, the upper rooms play a barrier function. In a properly insulated basement, the temperature, even in cold winters, rarely drops below + 1 ° C, therefore, the crop will be reliably protected. Nevertheless, there is some risk of freezing even here. Therefore, it is advisable to place a thermometer in the store in order to control the conditions - it is hung at a distance of 50 cm from the entrance. If the temperature drops below 1-2 ° C, then so that the potatoes do not freeze, it must be covered with old blankets, quilted jackets, and the boxes must be covered with layers of foam. In regions where the temperature regularly drops below -30 ° C in winter, even in a protected cellar, it is better to use special thermo boxes or heated boxes that will protect the crop in any frost.

If the potatoes are frozen in the garden, they should be dug up and sorted out in order to try to save at least part of the crop, and in the spring, rotting roots did not attract pests. Vegetables frozen in storage also need to be sorted out to determine the extent of damage.

Slightly frostbitten potatoes, which remain white when cut, are suitable for further storage (they must be transferred to optimal conditions), for consumption. The main problem here is the sweetish taste, which not everyone likes. There are several ways to get rid of this aftertaste:

• keep the potatoes warm for 7-14 days;

• defrost the tubers as quickly as possible in warm water (40-60 ° C), peel, cut off the top layer, dry, then cook as usual;

• clean, soak for 30-60 minutes in cold water, then change the water, add 1 tbsp. l. vinegar and salt, boil;

• use for cooking dishes where the sweetish taste is leveled - potato pancakes, dumplings, potato cutlets, casseroles, filling for dumplings, creating first courses or dishes with spices, spices, sauces, pickles.

But you need to understand that even slightly frozen potatoes are stored worse. If the potatoes are very cold and icy, then after thawing, they will most likely quickly begin to rot. In these cases, in order to somehow save the crop, it is better to process it quickly. This can be done in the following ways:

• make homemade starch;

• use for making moonshine (there is a lot of sugar in frozen potatoes);

• give for animal feed.