Torrefied wood

Wood heat-treated in a low-oxygen kiln, changing its chemistry and its behaviour rather than only its colour.

Torrefaction is a mild pyrolysis: the wood is held at high temperature with little oxygen until hemicellulose breaks down and the material becomes darker, lighter and less hygroscopic. In guitars the treatment is used to make a board behave like an older, drier piece of timber, so a torrefied top is deliberately aged in a kiln instead of over decades. It is commonly described as sounding drier, more open and more immediate, with some of the tightness of new wood removed. The costs are strength and consistency, since over-treated wood turns brittle and one maker's process is not another's.

Example: A torrefied spruce top is bought by players who want the open, played-in character of a vintage instrument without the wait.

typical use: Acoustic soundboards and necks, and body blanks on some electrics.

Torrefied wood

See also