Why do pine chips (or kindling) make a crackling sound when they are being burned?

Question

I have also noticed that the same sound is sometimes made when the fire is stired up (with a fire poker) and the log is broken open. Does anyone know why this happens?

Answer 1

moisture in the wood.

Answer 2

it is also because of the small air pockets inside of the wood (and all matter) that the exposure of the air from the pocket makes a sort of popping or crackling sound, think of a popping balloon, it is just trapped air being released rapidly

Answer 3

its moisture and air bubble wen there brought to a boil

Answer 4

It's because of any water content in  the wood.

Answer 5

the popping noise is caused by the air pockets in the wood.  Once oxygen is exposed to the fire it makes a crackling noise.

Answer 6

boiling water in the wood causes pressure to build up, when you shift it around some of it leaks out and makes a bunch of little pops which produces the crackling you hear

Answer 7

The moister in the wood is causing it to split open much like a pop heard from a kernel of popcorn when it pops.