White charcoal or Binchō-tan is a charcoal that loves adsorbing things. Binchotan, which has been produced in Japan for centuries, naturally adsorbs toxins such as chlorine, lead, mercury, cadmium and copper from tap water. It also releases useful minerals like calcium, potassium, magnesium and phosphates.
To use Binchotan, you simply place a piece of the charcoal into a water pitcher, and leave it to sit for 6-8 hours. After this time, the water in the pitcher will be purified and mineralized.
It is recommended that the Binchotan stick be boiled in a shallow pan of water for 10 minutes every month to keep the exterior pores open. After four months, boil the charcoal stick again. If you don’t see a profusion of bubbles circulating around the charcoal stick when it is returned to the pitcher and water is added, the stick has reached its capacity to absorb toxins. At that point it is ready to be composted in the garden or used as an odor absorber in your refrigerator.
You can get Binchotan on Amazon: 1 pound of Binchotan costs about $18. A single pound will last you 3-6 months depending on the amount of water you purify, and the amount of contaminants in your water. You can also get a portable Binchotan bottle for on-the-go filtration.
Binchotan: A Super-Adsorbent Charcoal
Binchō-tan is only made in the forests of Wakayama, a province in southern Japan. The branches of Holm Oak trees are sustainably harvested then slowly fired in traditional kiln ovens over many days.
The very dense wood of a Holm Oak has a multitude of open pores through which the tree breathes, nourishes itself, and redistributes chemicals back into the earth. The microorganisms (which are utterly harmless to humans) that live in these pores efficiently decompose toxic chemicals like chlorine, pesticides and herbicides. This phenomenon of adsorption (not to be confused with absorption) ensures that contaminants stick to the active charcoal until it is completely saturated. This is why it is necessary to reactivate the binchotan every three months by soaking it in boiling water.
The fineness and high quality of binchō-tan are attributed to steaming at high temperatures (about 1000 degrees Celsius). Although it is often thought that binchō-tan burns hot, it actually burns at a lower temperature than ordinary charcoal but for a longer period. It does not release smoke or other unpleasant odors. Binchō-tan or white charcoal is harder than black charcoal, and rings with a metallic sound when struck. Wind chimes and a musical instrument, the tankin (“charcoal-xylophone“) have been made from it.
You can read a FAQ about Binchotan on this page.