so we all use tea kettles to boil water, and we all have had tea that allowed multiple steepings.
the main problem is having to re put fresh water and then wait for the water to boil before you can re steep your tea.
what i was thinking of doing was boiling water in a regular kettle, letting the water cool to 10 degrees above the steep temp and putting the hot water in the tetsubin.
will the tetsubin keep the hot water insulated or will the water cool down at the same rate if left in a stainless steel kettle?
Probably a little bit slower depending on the design, (so long as you preheat it otherwise its greater mass of cold iron will just cool the water a ton when you pour it in). But most people that use them for hot water like that use a small alcohol burner or charcoal brazier or something to keep it hot. (also you need to make sure you have a non-enameled type if you want to do that). It’s usually just for aesthetic purposes though, you’re probably better off just reboiling the regular kettle.
A large insulated thermos would work a lot better than a tetsubin for keeping your water hot, I hear a lot of people do that, so long as you’re drinking something like green tea that doesn’t need boiling water. Or better yet, just get a digital electric kettle with a keep-warm function.
i was also thinking about the electrical kettle, but wanted to get some more info on the tetsubin before i make a decision.
Traditionally in Japan, cast iron was used for heating water, not brewing tea. Something about that enamel yeah…