According to a report by the Japanese media outlet grape, many people carry their favorite drinks in thermoses every day, attracted precisely by their excellent heat and cold retention. However, do you know that some drinks should actually never be put into a thermos? The well-known Japanese cookware brand Wahei Freiz Co., Ltd. recently detailed on its official website the list of drinks unsuitable for thermoses and the reasons behind it—including many everyday drinks that people would never expect:
After these drinks are put into a thermos, the pressure inside the flask increases sharply, very easily causing the lid to suddenly burst open and fly upward, creating a risk of injury.
Although many people think that because a thermos has cold retention, dairy products should be fine, in fact once the temperature inside the sealed container rises slightly, the spoilage process of the drink proceeds rapidly at a geometric rate. During spoilage, large amounts of gas are produced, ultimately causing the lid to burst open and fly off due to excessive air pressure.
Many people like to carry soup in a thermos, but even miso soup or ordinary hot soup—the internal material and structure of special soup jars and ordinary stainless steel thermoses actually differ greatly. Be sure to check the product manual for compatibility before use.
Residue such as tea leaves or fruit pulp very easily gets stuck in the rubber ring or gaps of the lid, causing poor sealing and resulting in liquid leakage.
Sealing alcoholic drinks in a thermos is very dangerous, because like dairy products, they easily ferment in a sealed environment, causing the air pressure inside the flask to rise sharply.
As long as you thoroughly clean the thermos with mild dishwashing liquid on the day of use and let it dry completely before storing, it is basically fine. However, if not properly maintained, the slight acidity of sports drinks can cause mold and rust inside the flask, so regular deep cleaning is necessary. If you cannot clean it immediately when out, it is best to first thoroughly rinse the inner liner with clean water and develop the habit of frequent rinsing—cleaning after getting home will then be ten times easier.
After this thermos maintenance and safety knowledge was exposed, it immediately drew a large number of Japanese netizen comments, many exclaiming that they had no idea at all before: "I really didn't know before that brewing tea directly with tea leaves would damage a thermos... I learned something new today." "It turns out there are so many things that can't be put in—I used to often put coffee milk in a thermos. I really need to be more careful from now on!"
Source: grape
