How to remove rust from Nambu cast iron kettle(Tetsubin)

Rust always occurs, even when artisans such as ourselves use the products.

It is not a particular problem and is no cause for worry, as long as the rust is not sufficient to stain the water red.

Maintenance aimed at rust can be performed by putting sencha(Green tea) inside of a product and boiling it.

Please see here. 

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