Last night I awoke to the sound of rain. It was a welcome sound as we have had a long dry summer. We are fortunate to be blessed in the Pacific Northwest with abundant water, good tasting water. Good water for tea starts here.
I have blogged previously about water for tea here. Because iron pots were long used for boiling water for tea, I blogged about the sound of boiling water here. Why has iron been the choice for boiling water for tea?
It is said to significantly change the taste of water. When brewing tea using water boiled in iron pot the taste of the tea becomes very mellow and sweet. In addition, thanks to the iron content of the kettle, the resultant water gives us additional health benefits.
“The chemical structure of water is part of the key that explains how water changes when boiled in a Tetsubin. The water molecule (H2O) consists of two elements, hydrogen (+)and oxygen (-).These elements carry both positive and negative electrical affinities or charges, just like a magnet. This is called dipole in Chemistry. These equal electrical charges, that exist on both oxygen and hydrogen, cause water molecules to constantly spin when in a liquid state . If they stop spinning, then water will become ice. Variable intensity of hydrogen bond allows the flavor and texture of water to change depending on the instrument utilized when boiling it. For example, if there is no mineral content in the instrument utilized to boil the water, for instance, a sterile glass beaker, the positive and negative charges of the elements of the water molecule will simply be attracted to each other and form their network or molecule through their hydrogen bonds. These bonds give water it’s characteristic viscosity and surface tension, but a plain or flat flavor. However, when minerals exist in the instrument utilized to boil the water, for example, the Tetsubin, the elements of the water molecule are attracted to the minerals from the Tetsubin instead. In fact, the affinity of the water molecule with certain types of minerals in the Tetsubin is stronger than those existing between the water molecules themselves. Minerals and water molecules form more stable bonds. This stronger attraction between minerals and water molecules also increases the viscosity and surface tension of the water. This effects our perception of the flavor and texture of the water itself, and most importantly, our taste buds can feel more taste, and a taste that stays longer in our mouths thanks to the stronger attraction of these hydrogen bonds and the metal ions of the Tetsubin. “ Japanese Cast Iron Kettle: Hojo Tea
Please go to this site, it has a lot of information on cast iron tea kettles (tetsubuin): history, how they are cast, how to care for them, and how the chemical composition of the iron content and the water interact.
I have always been told when you scoop water out of the kama, the best tasting water is at the bottom, and when you scoop water from the mizusashi the best tasting water is from the middle. This makes sense to me if there is boiling water, the impurities the action of the boiling water lifts them to the top. In the still water of the mizusashi, there will be some impurities that will sink, and some will float. Therefore, the best tatsting water will come from the middle. What do you think?