To understand why this happens, let’s see what happens when a stick is burned.
First, the wooden stick will be heated. Inside the wooden stick there are small bags of water and sap. Just as the water in the kettle is boiled and evaporated, so is the water in the wooden stick. When the wooden stick is heated, the water and resin inside begin to boil and turn into a gas. The hotter the stick, the larger the pockets of water and gas will expand.
If you put wet firewood on the stove, you will see more explosions than dry firewood.
While the water and sap turned to gas, something was also happening far inside the stick. The main component of wood is cellulose . When cellulose is heated, it begins to break down or “break down” . For example, if you accidentally leave an apple in your lunch box for a week, the apple will turn brown and watery, that’s when it decomposes. When an object in nature decomposes, it transforms.
When the wood is heated enough by the fire, the cellulose inside the wood turns off and turns into a gas. This is when we see smoke coming from the stick, sometimes even before the fire burns.
Fire burns when the gas escaping from the stick combines with the oxygen in the air. Oxygen is like food for fire, thanks to oxygen the fire burns brightly.
As the wood burns, the combination of the inflated air pockets with the decomposing cellulose causes the air pockets in the wood to burst, one by one. The airbag rupture makes a crackling sound that you can hear.
So the more water and resin the wood contains, the more bangs it will make and the louder it will be. If you’ve ever put wet sticks in a fire, you’ve probably noticed there’s more to the explosion than the dry ones.
The wood looks like that but it’s not really as dense as you see it. It has tiny holes, so small they can’t be seen by the naked eye, and these holes contain water and plastic inside.
We all know wood, firewood comes from trees. When plants are alive, they regularly draw water up from the soil, and the water is trapped in tiny holes in the branches and trunks, which are called vascular tissues . When trees are cut down for wood, these vascular tissues retain water and sap.
Water can also penetrate wood in other ways. If the firewood is left in the rain, the wood will soak up the water, or sometimes insects make small holes in the wood allowing the water to seep in.
Sitting in front of a fire watching the sticks burn and listening to the crackling explosions is really fun. Most of these “explosions” are tiny, but occasionally you can see a few “explosions” that shoot out red-hot ash. Therefore, you should be careful to keep a safe distance from the wood stove.