One of the most distinct characteristics of roasted bamboo salt is its strong alkaline properties (pH 9+) compared to sun-dried sea salts (neutral pH). Acid is the main cause of cavities as it breaks down enamel and weakens the teeth. It is prepared by packing sea salt in a thick bamboo stem and baking it nine times at high temperature using pine firewood. During the baking processes, the impurities[specify] in the salt are claimed to be removed or neutralized while its inorganic contents, such as calcium, potassium, iron, copper, and zinc are increased.