There is no fixed time for boiled water to deteriorate and become unfit for drinking.
Because it is also influenced by the objective environment. For example, the temperature, the summer temperature exceeds 30 degrees Celsius, the air humidity is high, the bacteria multiply quickly, and it is easy to be polluted, causing diarrhea.
Therefore, it is best not to drink overnight water in summer. In winter, it is best to put overnight water in a covered cup and make it into warm water with boiling water the next morning. Boiled water should not be kept for too long, even if there is no shelf life, it is best not to drink boiled water after a few days.
Extended data:
"You can't drink water overnight" has no scientific reason. Everyone knows that overnight tea can't be drunk, which is mainly related to microbial pollution. Overnight tea is a medium for microbial reproduction. After the tea leaves are left overnight, the nitrite content will increase greatly. However, even if the tap water is left for a day or two after boiling, the probability of being polluted is very small, so you can safely drink it.
Many people will think that overnight water tastes a bit strange. Susan Richardson, a chemist at the University of South Carolina in the United States, analyzed the reasons.
First, there is a temperature difference in the morning and evening, and it feels best when the water temperature is normal, so the taste of water will change overnight;
Second, the chlorine in water volatilizes after being left overnight, which will also make the taste of water different;
Thirdly, a small amount of carbon dioxide will be dissolved in water during standing, and the generated carbonic acid will slightly reduce the PH value of water, thus affecting the taste;
Fourth, if the water is allowed to dry for a few days, microorganisms and algae will also enter the water. However, although overnight water has a strange smell, it will not bring harm to health.
For healthy people, drinking pure water is not recommended. Boiled tap water is the best drink. But for some patients with special diseases, such as kidney calculi, renal insufficiency and dialysis patients, it is suitable for drinking pure water. This kind of patients are often accompanied by hypercalcemia and hypermagnesemia, so it is not appropriate to supplement more minerals and drink pure water often, which is beneficial to health care and adjuvant treatment of diseases.
References:
People's Network-The longest life of a glass of water is 16 hours? Experts answer whether overnight water is ok.
People's Network-Health Care Need to Know: Can you drink water overnight?
People's Network-Does the water stink overnight? These four reasons will never occur to you.