Ash glaze

When the glaze is mostly made up of wood ash, the final result is mostly dark brown to green.

At this point, artists can process the ash further to create a more uniform mixture or leave it unprocessed so there are more random final results.

To process the ash, water is first added to the mixture and left to settle for a couple of hours.

The solution is drained and dried and the result is ash containing less harmful chemicals like some soluble alkalis.

[11] Most wood ash is primarily made up of calcium carbonate (CaCO3), which is used in many glaze recipes.

If the ash is not cleaned or mixed thoroughly the glaze mixture may be inconsistent in chemical composition.

The decrease in ash percentage is to give the artist some control over the chemical make up and result of the glaze.

A Yunomi or tea cup with an ash glaze, pooling at the horizontal ridges, made from pine ash by Phil Rogers .
Sake bottle ( tokkuri ) in the form of a bamboo node, with "naturally occurring" ash glaze, most heavily collected on the shoulder. Japan, 18th century.
Detail of dripping rice-straw ash glaze (top), Japan, 1852