Why does wood crackle in a fire? (Rachael

16th November 2023

How?

How do the gases burst out?

. How does the wood absorb water?

Helene Nolan, 2019)

• These noises are created by pockets of trapped steam escaping and causing a mini explosion.

• To understand why this occurs, we must first understand what happens when a wooden log is placed on a fire.

• First, the wood begins to heat up.

• Pockets of trapped water and tree sap, the sticky substance you see on trees, can be found inside the wood.

• The water trapped inside the wood warms up and turns into steam in the same manner as water in a kettle does.

• As the fire heats up, the water and sap within begin to boil and transform into gas.

• Something occurs to the wood when the water and sap convert into steam.

• Wood includes cellulose, which is the substance that plants are largely comprised of.

• When cellulose is heated, it begins to degrade, or break down.

• When the cellulose inside firewood becomes heated enough, it begins to convert into gas.

• This is when we notice smoke emerging from the wood, sometimes even before it bursts into flames.

• When the gas escaping from the wood combines with the oxygen in the air, flames form.

• Oxygen is like fuel for flames; it makes them burn brightly.

• This is what causes the crackling and popping sounds.

• So, the more water and sap there is inside the wood, the noisier the fire will be.

• If you've ever put damp wood on a fire, you may have noticed it makes a lot more noise than dry wood.

• It has numerous tiny holes that are too small for human eyes to see, and these holes contain water and sap.

• We all know that wood originates from trees.

• Even after the tree is cut down for firewood, there is still water trapped inside the xylem vessels.

• Water can also enter the wood in various ways.

• If firewood is left out in the rain, it might absorb water.

• Alternatively, insects may bore little holes in the wood.

Sitting in front of fire

• It may be enjoyable to sit in front of a fire and watch the flames while listening to the wood crackle and pop. The little blasts of steam exiting are usually minor.

Summary 1)