User avatar
Feb 3rd 16 6:06 am
Vendor Member
Posts: 3139
Joined: Aug 28th 12 12:12 pm
Location: Hong Kong

Re: Thoughts on this tetsubin?

by jayinhk » Feb 3rd 16 6:06 am

So Hojo stated that the Fe3O4 is what makes a difference with tetsubin:

"Once casting is completed, the iron kettle is baked in charcoal fire. The charcoal fire is burning with less oxygen and it generates carbon monoxide and takes away the oxygen from the surface of iron. The fire reduces iron from Fe3+ into Fe2+. In other word, the surface of iron kettle is activated. Without this process, cast iron kettle is nothing but kettle. It does not really change the taste of water and tea. As a result of this process, the internal surface of kettle becomes blue-gray color. This is the typical color of activated/reduced iron."

I told the seller I'd be rejecting the package on arrival so it would go back to him (not her) since it isn't an antique and isn't a kettle.

User avatar
Feb 3rd 16 1:16 pm
Posts: 764
Joined: May 2nd 10 6:03 am
Location: Shaker Heights, Ohio USA

Re: Thoughts on this tetsubin?

by BioHorn » Feb 3rd 16 1:16 pm

jayinhk wrote:So Hojo stated that the Fe3O4 is what makes a difference with tetsubin:

"Once casting is completed, the iron kettle is baked in charcoal fire. The charcoal fire is burning with less oxygen and it generates carbon monoxide and takes away the oxygen from the surface of iron. The fire reduces iron from Fe3+ into Fe2+. In other word, the surface of iron kettle is activated. Without this process, cast iron kettle is nothing but kettle. It does not really change the taste of water and tea. As a result of this process, the internal surface of kettle becomes blue-gray color. This is the typical color of activated/reduced iron."

I told the seller I'd be rejecting the package on arrival so it would go back to him (not her) since it isn't an antique and isn't a kettle.
I looked it up on Wiki. It appears to basically be bluing to reduce rust. If a chemist wants to chime in their contribution would be appreciated!

Link:
https://en.m.wikipedia.org/wiki/Bluing_(steel)


I am pretty sure the bluing on my tetsubin is long gone. Also since the interior becomes coated with minerals, I bet the taste of water from a tetsubin may change over time.

User avatar
Feb 3rd 16 3:07 pm
Vendor Member
Posts: 3139
Joined: Aug 28th 12 12:12 pm
Location: Hong Kong

Re: Thoughts on this tetsubin?

by jayinhk » Feb 3rd 16 3:07 pm

Yes, I Wiki'd it too. The only bluing I am familiar with otherwise is on firearms, so I found that rather interesting!

How's the interior of your tetsu? Rusty at all?