Iron pot can raise the water temperature and has strong heat storage capacity. In general, the boiling water of old iron pots can reach 97℃, even above 100℃, which can fully soften the water quality, and is especially suitable for making old tea or boiling tea, especially Pu 'er tea, while ordinary stainless steel can only reach 93℃. Iron pot boiling water can release ferrous ions, forming a mountain spring effect, making the taste of water thick, full and smooth. Making tea can effectively remove the musty smell in tea. Drinking water boiled in iron pot has a good health care effect. When iron pot is heated, it will release a large amount of ferrous iron, which will react with tannic acid and tea polyphenols in tea to supplement the iron needed by human body.

Stainless steel kettle contains chromium-iron-nickel alloy, and hexavalent chromium is highly toxic. Some people say that stainless steel contains elemental chromium, but stainless steel is most afraid of chloride ions. The bleaching powder in tap water contains chloride ion, which is also highly oxidizing. Even if it is oxidized into trivalent chromium, it is very toxic. Nickel can cause lung cancer, and the accumulation of heavy metals in the body is a major cause of lung cancer.