- Active carbon
Active carbon adsorbs many substances, so it used in the production and processing of sake for purposes such as removing colour and adjusting flavour and aroma. Carbon may be divided into animal- or plant-derived, and that used with sake is usually made from plants.
The black powder made by carbonizing the raw material is almost pure carbon with little power of adsorbence. This is activated to give porous “active” carbon of great adsorbency. Depending not only on the raw materials, but also on the method of activation and its size and shape, it has widely varying capabilities for removing colour, odour and so on.
Active carbon to be used with sake:
1)Should be low in heavy metals (especially iron), to prevent colour returning.
2)Should have strong colour-removing ability.
3)Should be flocculent (settle), and filterable.
4)Should not leave or transmit a carbon odour.