Wood can be said to go through three stages on its way to being ready to burn in your woodburner. Here they are:
1. Freshly felled
Freshly felled wood is sometimes called green wood. It is high in moisture, often with a moisture content 40-50%.
The outside of the wood is lighter in colour than seasoned wood, there will be fewer cracks and the bark will be firmly attached.
2. Air dry
Air dry wood has reached the stage of the seasoning process by which the moisture content that was as high as 50% when the wood was first cut has dropped to around 25%.
Wood can hold water both inside its cells and within the cell walls. By the time it is air dry, most of the wood all or most of the water from inside the sells has been evaporated.
This stage is achieved by placing the wood in an exposed site, stacked off the ground on a platform or pallet (to avoid moisture soaking into the wood from the ground). The logs should also be covered to protect them from rain or snow that would cause moisture to be reabsorbed. But if the wood is covered entirely it is susceptible to rotting. For that reason, it is important to ensure the storage area is well-ventilated and, ideally, open to the wind.
How long does this process take? For dense hardwoods, such as oak, beech, sycamore and hornbeam, ideally two summers and a winter will be needed to season the wood as effectively as possible.
For woods like ash, birch and poplar, which have larger cells, air dry seasoning can be achieved within one spring and summer, weather permitting.
3. House dry
The seasoning process can be finished by entering the final stage: the house dry stage. This means bringing the wood into your home a few days before you are expecting to burn it. The warm atmosphere created by the heat from your stove burning fuel that has previously been house dried will help to get a final chunk of moisture to evaporate and should bring the moisture content down to around 20%.