For brewing better not to use water from the tap, since chlorine impurities contained in it can spoil the taste of the drink. It is better to use store-bought drinking water. The water should boil and turn off at the first sign of boiling. The water temperature for brewing in a thermos should be 90-95 o C.
Before to brew in a thermos for tea or herbs, wash and rinse it with boiling water. Pour into a tea or grass according to the recipe and pour boiled water. The lid is immediately closed tightly is not necessary, for 5-10 minutes, the infusion should "breathe" and only then you can close it.
The steeping time and steeping depends on what herbs, berries or tea you brew. Adjust the cooking time beverages, depending on recommendations for brewing and infusion for each composition.