Nanbu Tetsubin by Iwashimizu Hisao - Information and Care

Finding a quality tetsubin can be difficult, and there are similarities to chasen when it comes to these difficulties. As when purchasing chasen from us, we want you to have confidence in the quality of products that we source and sell. You will be consuming water boiled in this tetsubin so we take this very seriously. In recent times, there are many tetsubin sold within Japan that were made outside of Japan. These tetsubin can contain various materials which are harmful to consume, especially repeatadly and over long periods of time. This tetsubin comes with a trademark certificate to indicate that it is an authentic Nanbu Tetsubin, which is the name given to cast iron kettles made in Iwate prefecture. This one in particular was handcrafted b y Iwashimizu Hisao, who uses a timeless design with a modern twist. Unlike chasen which are consumable products, if you take good care of your tetsubin it will last not only your lifetime, but can be passed onto next generations! Tetsubin make delicious hot water to drink on its own and also to make Japanese tea with. It is common in many parts of Asia to drink boiled water rather than cold tap water - why not start your day with a cup of sayu (hot water)?

Note that tetsubin is a cast iron kettle for boiling water, and is separate to tetsu kyusu, a cast iron teapot for brewing tea. Tetsu kyusu should not be used for boiling water.

Please pay attention to the following:

When filling the tetsubin, the maximum fill level should be around 70%.
You must fill the tetsubin with soft water, never hard water. This can affect the lifespan of the tetsubin.
The tetsubin is enameled on the inside which will prevent rust but that does not mean that it is impossible for rust to form, especially if not properly taken care of.
This tetsubin can be used on gas stoves or electric stoves, but please only use low to medium heat, never high heat.
When the tetsubin is very hot do not run under or submerse in cold water. Let it cool slowly to room temperature on the provided complimentary rice straw nabeshiki (trivet). The nabeshiki is handmade in Niigata prefecture using rice straw, the same material used to shade high grade teas like some high grade Tencha or Gyokuro like Yame Dentou Hon Gyokuro.
Before using the tetsubin for the first time, it requires ‘seasoning’. Rinse the tetsubin two times with lukewarm water. Fill to 70% and then bring to a boil over a medium heat. Discard the water and fill, boil, and discard two more times.
When boiling water, place the lid slightly angled so that it is slightly open, so that the pressure from steam doesn’t build up and cause a sudden spillage.

While on the hob or stove, please never let the water evaporate completely as this can cause irreversible damage to the tetsubin and will affect its lifespan.

Once you have finished using the tetsubin, discard all of the remaining water while using a cloth to prevent the lid from falling off (it will be very hot). Let the residual heat dry the tetsubin, leaving the lid off while it dries. If there are any large droplets or patches of water on the lid or exterior of the body, use a clean dry cloth to pat gently and absorb the water - any remaining small droplets or patches will evaporate quickly. Water left in contact with the tetsubin increases the risk of rust forming, so it is important to empty and dry the tetsubin properly each time. If you forget to empty it and water is left inside that cools down, fill to 70%, bring to the boil and follow the usual steps of emptying and letting residual heat dry the tetsubin with the lid off.

The tetsubin body and lid are extremely hot during use so avoid direct skin contact. To open or hold the lid in place, use a cloth such as a fukin. As the base is particularly hot during use, be careful not to place the hot tetsubin on any surfaces that may be damaged by the heat such as wood or fabrics, etc.

If you know the tetsubin will not be used for a while (e.g. you are going on holiday), make sure it is completely dry before storing away. If there is any residual moisture there is a high liklihood of rust forming.

Thank you for reading this far. We hope you understand that we take this part of our jobs very seriously and hope we have armed you with all the information required to keep your new tetsubin in good condition for many lifetimes! If you are unsure of anything or have any questions please contact us any time on Instagram or by email at info@cha-ology.com

Once you are used to the daily routine you will find these steps are rather straightforward and easy to follow. While the enamel interior will hamper the formation of rust, over many years of use there is a high chance that it will form. This is not something to be too worried about! A small amount of iron in the water will give the water a sweeter taste. In high concentrations however there can be a sour or metallic taste. If this happens, or if the colour of the water becomes red/brown, then it is time to remove the rust. We have included some sencha teabags with your tetsubin. Japanese green tea is a great tool to combat rust, as the tannins in the tea will react with the rust. Simply bring the tetsubin to a boil at 70% full with a sencha tea bag inside and keep the tetsubin simmering for 30-60 minutes. Turn off the heat and let the tetsubin sit for around 10 hours. Discard the liquid and the teabag, rinse the tetsubin twice, and bring to a boil at 70% full. If the water is still red/brown, you can scrub the rust with a soft brush. Never use any kind of detergent in the tetsubin in an attempt to clean the rust.

Please enjoy delicious water and even more delicious tea at home! We have the exact same tetsubin and you might like to know its official name is Egg so we call ours Egg-chan. :)