Green tea is best steeped at 80 degrees C ° because it would lose many of its active ingredients with boiling water. I don’t have a thermometer, so I use a pressure cooker to heat up my water. Approximately how long should I wait, once the water has boiled and at room temperature of 20C°, until the water has reached the correct temperature of 80°C?
Answer
It is not possible to answer your question without taking a measurement.
The ‘speed’ of cooling is proportional to the temperature difference between the water and the environment (so it is fast in the beginning, but will become slower and slower). However, the proportionality constant depends on the material and surface of your head. So you must first determine this constant by measuring the time it takes for the liquid to cool to a certain temperature. But then it is best to immediately measure the time to cool down to 80° and you will immediately have the answer to your question…
See also the answer to question 7605
Answered by
Prof Walter Lauriks
Physics Acoustics
Old Market 13 3000 Leuven
https://www.kuleuven.be/
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