How is water filtered using charcoal? Learn the history of Binchotan charcoal , find out how it works and what you can do with it.
This incredible natural material was brought to Japan by the monk and scholar Kukai around 1,200 years ago. However, it only became popular in the 17th century thanks to Binchuya Chozaemon of Tanabe, who innovated the existing charcoal production technology by exposing the charcoal to high temperatures in a kiln after a long process of burning at low temperatures. Hence the name “Binchotan” that is more commonly used today.
HOW IS BINCHOTAN MANUFACTURED?
The production of Binchotan charcoal requires a very rapid increase in temperature and then rapid cooling. The result is almost 100% carbon – Binchotan, which is heavier than regular charcoal and has a hard, smooth surface. If you tap it, you will hear a clear metallic sound.
Japanese Binchotan was the inspiration for London-based brand BLACK+BLUM , which produces products inspired by Japanese culture. The brand has designed a collection of bottles and decanters called Eau Good, which uses the traditional Japanese method of filtration with Binchotan charcoal from its own certified production. 
Charcoal is sourced in Laos from producers who cut only the branches of fast-growing native trees without removing the roots. This allows the trees to regrow and be reused in a five-year rotation. Logging occurs around the kilns, ensuring the forests in which the wood grows are protected.
The process of making Binchotan charcoal follows traditional Japanese techniques. It involves burning wood in a kiln for a long time at a low temperature. Just before it is finished, the temperature is suddenly raised to around 1000°C, until the wood is red hot. 
Then, a special powder is created by mixing soil, ash, and sand, which is used to quickly coat the charcoal. This process gives it a white hue, which is why it is sometimes referred to as “white charcoal.” The individual pieces of charcoal are then pressure washed, vacuum sealed, and ready to use. 
HOW DOES WATER FILTERING WORK WITH BINCHOTAN?
Binchotan charcoal has an incredibly porous surface with tiny pores oriented in many directions. The surface area of 1 gram of Binchotan is over 500 mᒾ. All of these pores provide areas through which the charcoal can absorb impurities in drinking water. Binchotan is also known as “activated charcoal” because the negative ions of impurities are attracted to the surface of the charcoal, where they are trapped.
Binchotan charcoal is also able to release minerals such as calcium, iron and magnesium back into the water, improving its taste and health benefits.
HOW LONG DOES CHARCOAL LAST TO FILTER WATER?
Charcoal can filter water for 6 months, however if you use it to filter approximately 1 liter of water every day, it is important to extend the life of the charcoal halfway through (usually after about 3 months). It also depends on the quality of your drinking water and how many charcoal sticks you use (for example, you may have a water tank that holds 4 charcoal sticks at a time). 
In general, judging the effectiveness of charcoal by the taste of the water is a good way to determine if it is time to extend the life of the charcoal. In my experience, 3 months is a common time frame. Not sure how to extend the life of Binchotan charcoal? Follow our handy guide here.
The Binchotan Activated Carbon Water Filter can be used in any water container, including a variety of reusable water bottles , as well as pitchers and dispensers. A wide range of charcoal filter bottles, accessories and carafes are offered by BLACK+BLUM . Try the simple and sustainable way to ensure your tap water always tastes great. 
