Tips 17/05/2025 10:56

5 types of water that should not be stored in a thermos



Not all drinks are suitable for storing in thermos bottles because if used incorrectly, not only will the drink be spoiled, it will also affect our health.

Below are 5 types of drinks that should not be stored in thermos bottles.

1. Milk

Drinking cold milk in cold weather can be uncomfortable, so many people like to heat it up and store it in a thermos bottle to drink gradually. However, this is not the right way.

Milk is very nutritious and the warm environment in a thermos bottle creates conditions for bacteria to grow, making milk spoil easily. Moreover, the proteins in milk are also easily changed when left at high temperatures for a long time, reducing its nutritional value.

If you need to use a thermos bottle to store milk, drink it within an hour.

2. Traditional Chinese Medicine

Many people, because they want to bring it with them for convenience, put the decoction in a thermos bottle. However, the ingredients of traditional Chinese medicine are very complex and are acidic or alkaline. Thermoses are usually made of stainless steel and contain metal elements such as manganese, iron, chromium and nickel. When Chinese medicine comes into contact with these metals, a chemical reaction may occur, reducing the effectiveness of the medicine or creating harmful substances.

In addition, Chinese medicine is susceptible to deterioration if left at high temperatures for a long time. It is best to store Chinese medicine in glass or ceramic cups to preserve the effectiveness of the medicine.

3. Acidic drinks and carbonated water

Acidic drinks such as fruit juice and carbonated water should not be stored in thermoses. These acids can corrode the stainless steel layer inside the bottle, damage the coating and release heavy metals into the water, posing a health hazard.

If too much is stored or shaken vigorously, the CO2 gas in the carbonated water will escape, creating high pressure, leading to the risk of explosion or spillage when the lid is opened. Instead of using a thermos, you should store these drinks in glass or ceramic cups.

4. Water containing salt

If the drink contains salt, it should not be left in the thermos for too long. Although the thermos has an anti-corrosion layer, salt water can still destroy this protective layer. It can even release heavy metals, which are harmful to health.

5. Tea



Tea contains a lot of tannins, caffeine, aromatic oils and vitamins, and is only suitable for brewing with water around 80°C. When brewing tea in a thermos, high temperatures and long heating times cause vitamins to be destroyed, aromatic oils to evaporate, and tannins and caffeine to be extracted too much. This will lose the flavor of the tea, causing bitterness and increasing the risk of harmful substances. Moreover, tea left in the thermos for a long time will leave a residue that is difficult to wash, making the thermos look dirty.

In short, the thermos is very convenient, but not all drinks are suitable for storing in it. Choose the right type of drink to both preserve the flavor and protect your health and the life of the thermos.

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