It is best to keep it in a dark and cool place, so as to keep the taste, and the preserved one can be kept for up to one month. If it gets wet, it can be heated in a microwave oven, but the taste will be affected. If it is midsummer, walnuts can only be stored for one or two months.

Extended data:

Walnuts with shells will not go bad after being stored for one year. Walnuts are best stored in the refrigerator, and they are easy to get insects and deteriorate in summer. It is best to buy walnuts with shells and put them in a cool and ventilated place. Packages with shells are stored for a long time, but it is best not to exceed one year. With the extension of storage time, the nutritional value of walnuts will decrease.

Walnut kernel should not be stored for a long time, and it is easy to produce oil, crack and deteriorate when stored in high temperature environment. Walnut is rich in nutrition, with a ratio of 100g protein 15 ~ 20g, and more fat and carbohydrate 10g. Walnut is rich in nutritional value, and has the reputation of "Long live the son", "longevity fruit" and "treasure of health preservation".

86% of the fat in walnuts is unsaturated fatty acid. Walnut is rich in copper, magnesium, potassium, vitamin B6, folic acid and vitamin B 1, and also contains fiber, phosphorus, nicotinic acid, iron, vitamin B2 and pantothenic acid. Every 50g walnut contains 3.6% water, 7.2g protein, 3 1g fat and 9.2g carbohydrate.

Generally speaking, if some walnuts still exist in the shell, and the storage conditions are ventilated and dry, they can be eaten within one year, and the taste and value will not change.

But don't eat walnuts for a year or two or even longer, and walnuts mainly contain walnut oil, which is a saturated fatty acid. If eaten within one year, it can be beneficial to the body and reduce the blood lipid of the body, but it will become grease after more than one year, which is not good for the body.

References:

Baidu encyclopedia-walnut