Wood was the first fuel used to fire pottery.  Wood firing was brought to an exquisite state of refinement in China during the Sung Dynasty, then spread to Korea and Japan, and was much later followed by our own rich American Wood Fire Tradition.
The mechanism by which wood fired pots gain their unique surface is universal.  As the kiln rises in temperature, the ash from the burning wood is picked up by the draft and flies through the firing chamber.  As it does so, it settles onto the pottery.  Then the chemicals in the ash bond with the silica in the clay to form an uneven, rich, natural glazed surface.
Since every tree is different, both in terms of species and in terms of where it was grown, the chemical content of  ash varies greatly.  These materials are the nutrients that allowed the tree to grow and they spring from the earth in which the tree thrived.
Therefore, the ash glaze that covers wood fired pots is a direct reflection of the tree and earth that provided it.
The spontaneity, happy accidents, irregular surfaces, and deformations that occur in my work keep me endlessly interested. 
As the caligraphy below states, I make my forms with clay and water, then I surrender them, with a prayer, to the kiln.

   Japanese Anagama Wood Kiln

Assortment of Wood Fired Pots

  A Wall Next to the Wood Kiln
 Where I Fire

My Wood Firing Workshops Provide First Hand Experience With These Concepts