About Nanbu Tetsubin (Japanese Cast Iron Kettle)

About Nanbu Tetsubin (Japanese Cast Iron Kettle)

April 04, 2022

The Cast Iron kettle, also known as "Tetsubin" in Japanese, has been produced by Japanese craft masters for hundreds of years. Traditionally, it is a hand-crafted object used as a utensil in Japanese tea ceremonies. The molten iron is poured into sand or clay to design these cast iron kettles. Clay molds have been used to produce high-end artisanal Tetsubin products for hundreds of years, while the sand molds produce those Tetsubin products intended for commercial exports and sales.

Purpose of Cast Iron Kettle

The purpose of Nanbu Tetsubin is significantly unique. This product is used to soften the taste of water and maintain its boiling temperatures. The taste of tea becomes very sweet and mellow when it is brewed using water boiled in a Tetsubin kettle. Japanese Cast Iron kettle gives additional health benefits to the restaurant water.

How the Taste of Water Changes when Boiled in Tetsubin (Japanese Cast Iron Kettle)

The chemical structure of the water explains how the taste of water changes when boiled in a cast iron kettle. Water (H2O) consists of two elements, hydrogen and oxygen.

They both carry equal but opposite charges, positive and negative. Due to opposite charges, water behaves like a magnet and forms a dipole. Both positive and negative charges force the water molecules to spin constantly when it is in the liquid state. If the spin of the water molecule is stopped, it will turn out to ice.

The variable intensity of the hydrogen bond allows the water to change its taste based on the instrument used when boiling it. For example, suppose such a cooking device is used that does not contain any mineral content like a sterile glass beaker.

In that case, both water, hydrogen, and oxygen elements will be attracted to each other, and a hydrogen bond will be formed between them. This bond will give a flat flavor to water, but its characteristics, such as surface tension and viscosity, will be changed.

But if such an instrument that utilizes minerals (Nanbu Tetsubin) is used for boiling water, the water element will be attracted to the minerals from the tetsubin instead. The bond between water molecules and minerals will be much stronger than the bonds between the water molecules themselves. The water and minerals will form a more stable bond that will increase the surface tension and viscosity of the water.

This phenomenon will change the taste and texture of water when boiled in tetsubin; most importantly, our taste buds will experience a sweet and long-lasting taste of water. The depth of water flavor is also affected by the presence of minerals. Minerals form stronger hydrogen bonds in water and attract volatile flavor. The stronger hydrogen bonds cause the slower evaporation of volatile substances, producing a longer and deeper water flavor in our mouths.

It is worth noting that the taste of water boiled in tetsubin will differ based on the type of water you choose. Each type of water contains a different amount of minerals that affect the taste, composition, and physical sensation of water. The attraction between hydrogen atoms and metal ions of Nanbu Tetsubin provides a mellow taste of water.

Effects of Nanbu Tetsubin (Japanese Cast Iron Kettle)

The Tetsubin Kettle is significantly used for boiling water. If you use water boiled in Tetsubin to brew tea, it will change the taste of the tea. It will turn out sweet and mellow. The water boiled using a cast iron kettle is not only suitable for the preparation of tea but can be used for drinking purposes, for making coffee, soup, or commercial products such as Cup O’Noodle.

You will be amazed to know that the taste of water boiled in a tetsubin kettle will be different from the water boiled in any other ordinary cooking device. Japanese cast iron Kettle enhances the taste of water and gives a deeper and long-lasting flavor to it. A tetsubin is a perfect choice for those tea drinkers who want to enjoy a stronger after-taste in their tea.

On top of that, tetsubin changes the unwanted aromas of water that give a mellow taste to your tea. If you compare two different cups of tea, one brewed in a stainless steel teapot and the other in a Cast Iron Kettle, you will find that the cup brewed using water from Tetsubin will have a longer aroma and sweet flavor. Frankly speaking, if you want to enjoy the aroma element of your tea, Nanbu Tetsubin is not for you.

Also, remember that water taste may differ from one tetsubin brand to another. This is because of different raw materials and techniques used during the production of cast iron kettles. Different tetsubins have a different surface area (porosity) that leads to different flavors of water.