Wood Dust and Chips - What are the basic differences?

Wood is wood isnt it??  well, in a way yes, but the way wood behaves when it burns largely depends on the size of the pieces. There are a few other factors which influence the way the wood behaves when it's burning like the moisture content and the species of wood. I'll cover these other factors in another blog post.

Wood burns when it is heated beyond a point known as the fire point which is normally around 300 celcius. However this can change depending on the size of the pieces and moisture content. When wood is in a fine dust form it can be explosive and there are examples of wood mills exploding due to the dust being ignited by a spark resulting in a dust explosion. Now, were not looking to put our smoked food into orbit but it's nice to know that we are dealing with something that has a lot of stored energy which we can employed to flavour and enhance our food.

The only time we really need to take account of the form the wood takes is when we want it to behave in a certain way. If we're cold smoking for instance and want to produce as little heat as possible, we want to produce a burn that is slow and sustained without a rapid release of heat. For this, the best form of wood by far is fine wood dust. Wood dust just has a natural temdancy to smoulder due to it's relitively small particle size. It has a large surface area to mass ratio and this helps when trying to ignite it.

Fine wood dust, when ignited has a tendancy to smoulder reliably for many hours. In fact it's more than likely going to continue to smoulder until the wood dust runs out or it is extinguished manually. It does this because unlike a coarse wood chip which has a lot of space between the particles, wood dust has much less air around the particles of dust and tends to insulate itself holding onto heat and thus smouldering is possible by that heat catching and burning the adjacent wood dust. If you want to cold smoke you're much better off using dust in one of the maze style smoke generators.